This is the same ratio as a 4R70W transmission. I have a 1982 2wd with a 305 Engine, A th-350 and 4bl Carb. So when you use it you will see the line retrieve is good and the spin of the gear will feel smoother. It's best to think of the GV (or the US Gear for that matter) as a second transmission that operates entirely independently of the main unit. Buy PATC speedometer ratio adapter decrese 10%: Drive Gear - Amazon. That only gives you a 7. 115 for Diesel. I have a 1968 firebird convertible with a 350. 29 gear has a lower ratio than a 4. M-22 close ratio 70-74. We've assembled a variety of manual gear ratio charts for General. The TH400 will give the driver full control over the transmission while providing firm shifts and better gear ratio pairing. 10 axle ratio with stock-size tires. 06 first gear in, for example, the 700r4. 58:1, so if you need something lower than that, it’s where the two-speed 400 comes into play,” Nichols explains. The value will be returned in estimated differential gear ratio, based on the entered values. In my case I lucked out, my 700r4 drive gear (18 teeth) coupled with the randomnly selected th350 driven gear (19 teeth) showed exactly twice actual road speed. 88:1, an overdrive transmission is not the best choice if you do not spend much time at 80 miles per hour or above. One of the most common places where the hobbyist must grapple with gear ratios is the case of a lathe that uses change gears to cut various threads (as opposed to a lathe equipped with a quick change gear box). We had a truck with 3:08 gears and a 700R4 that was only getting a solid 12 MPG, after changing the rear end gears to the 3. The New Venture Gear NV3500 at a glance. Bands and clutches hold the reactors stationary. RPF takes everything into account, from the crankshaft to the tires on the road. IMO it IS the finest production 3 speed auto ever designed bar none. Luckily, nonstock gear ratios are available for the TH400. 38, very low. Street tires are rated using three numbers for example 225/70R15 or 255/70/15. The TH400 is conservatively rated at 450 ft. The transaxles for these two machines are virtually identical, but I did notice that the part numbers for the ring & pinion gears in the differentials are different and also the part numbers for the. This will help you pick the right size tires, transmission and gear ratio combination for your classic. In 1stgear max. The key is the engine’s peak torque figure. Is the 700R4 interchangeable with the Turbo 350? and all you have to do is nab the speedo gear off of the 700r I did so with a lack of tools so I used a 2x4 and a. Enter the maximum potential safe engine RPM. If you know your gear ratio and tire size you can get a fairly close idea here. Looking to get 2600 bucks for all of it including the transmission. In my case I lucked out, my 700r4 drive gear (18 teeth) coupled with the randomnly selected th350 driven gear (19 teeth) showed exactly twice actual road speed. trans type. 73 rear (assuming 29-inch diameter tires) is a 18-tooth drive gear and 35-tooth driven gear. The TH350 uses a mechanical kick down switch, whereas the TH400 uses an electric one. trans brake (yes or no) 1st gear ratio. I would leave it alone, 3. Click on Calculate. I checked the gear ratio. 55" or simply "three fifty-five. I checked the gear ratio. Re: Best rear end ratio for street car? « Reply #22 on: October 03, 2011, 01:32:45 PM » I have the 4. However, simple gears with only 5 teeth tend to run a bit rough, so your best bet is to make (or obtain) gears with 10 and 24 teeth. Also features a 2. These transmissions are assembled in ATI's SFI case with an SFI Mopar specific bellhousing. Note: The mounting pad is usually a part of the extension housing, but the graphic shows it on the maine case. Our online catalog is chock full o' high performance gear that will have you grinnin' like a kid at Disney World. Best gear ratio/mpg combo? If this is your first visit, be sure to check out the FAQ by clicking the link above. I wrote this calculator in the early 2000s to help me figure out the ratio on my '77 K10 Silverado (35" tires and 8" lift, auto trans and NP205 transfer case). This trans was built with a Chevy only bolt pattern, but we have a package for Buick, Olds, Pontiac, and Cadillac people so you can enjoy the benefits of this excellent transmission. What is the best transmission for 350 small block. The gear ratio for low gear is 2. We had a truck with 3:08 gears and a 700R4 that was only getting a solid 12 MPG, after changing the rear end gears to the 3. 10 rear end will snap your neck with a stout motor in 1st, but you'd be stopping for gas much more often and be taching out at high rpm at highway cruising speeds. The 1971 Monte SS (stock 454) currently has a TH400 trans and 3. Vehicle Weight (in pounds) Vehicle Horsepower: RPM through lights (finish line) Tire Diameter (Hght. RPF takes everything into account, from the crankshaft to the tires on the road. Also, the 4L80E transmission is typically about 4 inches longer than a TH400 (depending on the length of the extension housing), but the trans mount is located roughly 11⁄2 inches rearward. This transmission is for any type high performance / heavy duty use up to 600 horse power / 450 torque using pump gasoline. Alternate gear ratios and aftermarket housings (as pictured) are available for additional cost. 06 ratio (first) to 1. The "low-gear" (2. At about 2600 dollars (depending on model) the GEAR VENDORS is not the cheapest way for you to get overdrive but is by far the best. 06 ratio in first gear, which is 20% lower than most transmissions. 73 (auto) or 4. 00 lb-ft x 3. 48, so the deeper gear is a decided advantage for towing and. 25 rear axel, and i run 32's but the xj feel forced at highway and uphills,with which gear ratio i will have a better performance with those 32 tires that i have (3. 70 rear end. 5:1 compression, a Comp 292 cam (rough idling hot rod style cam), 4. or "The Best Transmissions The C6 shared the exact same gear ratios, but was adorned with a. 00 lb-ft x 3. We had a truck with 3:08 gears and a 700R4 that was only getting a solid 12 MPG, after changing the rear end gears to the 3. 10 gears and the same size tires (245 75 16) you might be turning 3400-3700 at 65 with the TH400. The overdrives are kept synchronized to provide a smooth, stock-like driving experience in 5th and 6th gears. Note that the resultant gear ratio is just the product of the two separate gear ratios - (T1/T2)*(T3/T4). What gear ratio would you run? I had a friend who drag raced a '76 T/A with a 455/TH400, and he made his best times with a 3. Before we explore the process and our options involved with mating the Atlas-4SP to the back of the TH400, the first job is to swap out the input shaft. Animal Performance Custom Built Transmissions Home of The Revenger, Beast and Dominator Builds 30+ Years Experience Street and Strip offroad Monster Truck 700R4 Beast 2. With the A340E 1 st gear it gives a brief but effective overall 1 st gear ratio of about 5. A Powerglide transmission in combination with a numerically high gear ratio is a good choice for quarter-mile cars or performance engines that live in the upper rpm limits, and also for street-worthy muscle cars that have very broad power bands. Let's say you have a car with a 3. Gear Ratios - 1. 48:1 for second, and 1:1 in third gear. What gear ratio would be best for me to have? I still want to be able to run the truck on the freeway at like 65mph. In fact, they are every bit as important as the engine itself! If you don't have the right gear ratio, even with a super. I'll be swapping in a D60 and 14 bolt axle set into my M1009 in the near future and I'm trying to decide what gear ratio would be the best. That only gives you a 7. It wouldn't make sense to spend a grand on a rear gear when a grand more could be spent on an overdrive with about the same final gear ratio. Adding six teeth to correct a speedometer reading 15% high gives us a 42 teeth. Use our simple Gear Ratio Calculator to quickly find the correct gear ratio for your ring and pinion gear set. However, simple gears with only 5 teeth tend to run a bit rough, so your best bet is to make (or obtain) gears with 10 and 24 teeth. Contact Central. I’m looking for recommendations for the optimum gearing on my differential. Choice of 9310 Chromoly 1. From complete engines, to torque converters to Monster in a Box, we've got all your HP needs covered. 06 ratio (first) to 1. " The key to understanding gear ratios is to remember that, as the numerical ratio goes up, towing. rear gear ratio. By activating and deactivating the solenoids in a predetermined pattern by the PCM, 4 distinct gear ratios can be achieved. TH400 Transmission The TH400 3-speed automatic transmission first appeared on GM passenger cars in 1965. Best rear end gears for a 700r4 w/ 350. Working out the tooth counts for planetary gears is actually not that complicated, so I initially neglected to mention how to do it. It tells you how many revolutions the crankshaft turns to move your car one foot. Whereas a 4. 5:1 compression, a Comp 292 cam (rough idling hot rod style cam), 4. Enter the values on the left and press Compute, the gear calculator will take care of the rest. 31 gears originally. With the A340E 1 st gear it gives a brief but effective overall 1 st gear ratio of about 5. Most transmissions have more than one planetary gear set to provide a variety of gear ratios. 91 gear will get the job done for the lower power cars or the 1/8th mile guys. The siphon tube section of the filter that plugs into the case has a sleeve-shaped rubber seal with ridges on it, so the filer doesn't have to be rigidly held into place. 97 first gear ratio. Enter the maximum potential safe engine RPM. 44RE: The 44RE four speed automatic transmission was used in 1996 to 1998 Jeep Grand Cherokee's with 5. TH400 Transmission The TH400 3-speed automatic transmission first appeared on GM passenger cars in 1965. Second gear will have more torque than second gear with a lower rear end numerical ratio, but you will not be able to stay in second as long when the rear end gear ratio is increased. As you may have read in the 4G6x section, there are two types of bellhousings available: wide and narrow. Let's say you have a car with a 3. ) in Inches. So, whether you have a radical cam in your big block Chevelle or are towing 20,000 lbs. In some cases, depending on converter, they can consume up to 40 horse power. The first thing to do is make a quick WOT pass in a low gear (a low load) and check both O2's and knock retard. Turbo-Hydramatic or Turbo Hydra-Matic is the registered tradename for a family of automatic transmissions developed and produced by General Motors. ” ATI Superglide 4 with Lock-Up Beattie says that converting a TH400 to a two-speed setup is relatively simple, but there definitely is a right way and a wrong way to do it. For example, if one gear with 13 teeth is driven by a gear with 21 teeth, the gear ratio is 1/1. 75 overdrive sixth, bringing the first four gear ratios closer together. Most Skylark/GS cars from 1968-72 have open (non-posi) rear axles. The TH350 uses the standard gear ratios of 2. Or, change input variables (engine RPM, axle gear ratio and tire height) to determine vehicle speed in each forward gear. M-21 close ratio 66-70. 7 to 1 wherein the 6 speed is like 2. That only gives you a 7. in some applications. Could use less gear or more motor but for mismatch parts it goes pretty good. Count on the best quality ring & pinion sets when you order Richmond performance gear sets. At about 2600 dollars (depending on model) the GEAR VENDORS is not the cheapest way for you to get overdrive but is by far the best. 10 rear axle results in a final drive ratio of 10. Using a TH400 as. 12 by your Jeeps tire diameter (Example:. 06) belongs to the GM 4L60/E family of transmissions. 78 gears and the car is pretty doggy. The overdrives are kept synchronized to provide a smooth, stock-like driving experience in 5th and 6th gears. These gears are an excellent alternative to steep rear end gears for street driven performance vehicles and low RPM, high torque race engines. The fully synchronized NV3500 manual transmission was first available to Dodge buyers in the 1994 Dodge Rams and Dakotas, as a replacement for the NV4500; it had an two-piece, aluminum-casting, split-case design that weighed less and had less noise than cast iron. 36 rear axle gear ratio coupled with the 3. BTE Racing leads in building high performance automatic transmissions and transmission components for all racing and street applications. 11 ratio gear set, quick release pro tree transbrake valve body, 9310 Chromoly input shaft choice of turbo or powerglide spline, 8 clutch high gear drum with wide steel hub, Kevlar band, Torrington roller bearing, deep aluminum pan, rollerized billet aluminum governor support, billet aluminum. 04:1 ratios of the five-speed transmissions it replaces, for improved launch and traction. You can think of this trans as basically a TH400 with a 25 percent overdrive tacked on. I'm running a '68 L71 427 w/ISKY Z89 solid cam, TRW 11:1 forged, dimple rods, stock steel crank, closed chamber rectangle port heads, comp. With 31s and the fact that it is gonna be a cruiser I would probably go 3. 90 for the stock setup which just wasn’t deep enough so I was forced to go the trans route unfortunately. top | hiking | swiss day hikes | trin-valendas. Street tires are rated using three numbers for example 225/70R15 or 255/70/15. 700R4/4L60E's have a low 3. However, this means that the car is aMy '77, L82, 4-speed has a 3. I used the AOD ratios I found on the web and my tire size just to give you an idea. How to Calculate Gear Ratio. Drag Max RPM slider to adjust the range of the RPM and MPH Gauges. 48 First gear by the 4. Length - 10. This transmission is for any type high performance / heavy duty use up to 600 horse power / 450 torque using pump gasoline. How to pick a gear ratio: The truck has a 375 horsepower 350 with a decent cam and a full exhaust. RPM drop than the wide ratio gear set. The 700r4 driven gear is the same as a th400, which means if you re-use the speedo drive gear your speedo will read faster. 84 Ratio 1st Gear Racing Transmission 1100+ HP !. vehicle use. 48 and the HD internal differences of the TH400. Ideally simply want to change the rear end back to 3. and my rear end a 10bolt and my tires on the rear are 275/60/15s what good rear end gears would be good for highway and street use and i dont race it i just want that extra punch for the street and good highway performance aswell something in the middle of both highway and street. It's a cruiser, but it should still have some get up when needed. Richmond also has a Super Street version of its 5-speed gearbox with an overdriven fifth gear. Last night we Jacked up one tire and spun it to see if we could figure out which. The first gear ratio of a TH-700R4 is 3. 55 or numerically higher will have you right at the max rpm at around 35 mph, only to then have your car fall on its face when it hits second gear, feeling like it skipped a gear. 07 first gear, as opposed to a 2. Calculator Use. The venerable Powerglide, long regarded as the bulletproof, go-to drag racing transmission, has slowly gained some company from the Turbo 400, as Nichols. Richmond also has a Super Street version of its 5-speed gearbox with an overdriven fifth gear. Very peppy on take off, good shift pattern, hits high gear 40-42 at those low RPM, and my top end is more than my lifted suspension can adeqately handle. Calculate Rear End Gear Ratio needed Todays date is 10/11/2019 These, and many other questions are examined in this all-new color update of a perennial best-seller. 2-Speed / 3-Speed Automatic. What gear ratio would you run? I had a friend who drag raced a '76 T/A with a 455/TH400, and he made his best times with a 3. You may have to register before you can post: click the register link above to proceed. These two bellhousing when measured from the lower two bolts are 13. or "The Best Transmissions The C6 shared the exact same gear ratios, but was adorned with a. 42 gears standard and 3. Gear Ratios - 1. As an example, with a 3. Such a gear imposes a time-dependent kinematic constraint on the motions of the two driveshafts:. Lenco Racing, the all time champion and undisputed leader in the drag racing. 48 second and 1. TCCoA Forums > Car Related > Drive Train > 4R70W Transmissions > AODE and 4R70W gearset ratio T199 Send us the gear ratios For the best viewing. 73 Gear ratio. Transmission Gear Ratio Equation and Calculator Mechanics and Machines Calculations Menu The following equations and calculators will estimate the resultant vehicle speed at a known engine rpm for a manual transmission with up to six forward gears. SC automatic transmissions (4R70W) '94-'95 use a 7 tooth drive gear. Don't overlook gear ratios, as how the transmission will work with the rest of your drivetrain is very important when considering the efficiency and power transfer gains a transmission swap can offer. Vehicle Weight (in pounds) Vehicle Horsepower: RPM through lights (finish line) Tire Diameter (Hght. Could use less gear or more motor but for mismatch parts it goes pretty good. A new speedo drive clip is included. M-22 close ratio 70-74. The highest tested shift point was 76mph, on a ’63 409 (340 hp) Impala coupe, with a standard 3. Also factor in your first gear ratio on the trans that you are using (I run a TH400. As for cruising, a 700-R4 is equipped with a. But the ratio drop is still a bit too much. 06 to 1 and an overdrive ratio of. The TH350 uses a mechanical kick down switch, whereas the TH400 uses an electric one. 059 2nd -- 1. The TH400 is an automatic shift, three-speed, longitudinally positioned transmission. The gear set was installed in a carrier, also referred to as a “pumpkin” that could removed from the front side of the axle assembly as a complete unit. A collection of off-road calculators to help you convert inch and metric tire sizes, find the appropriate gear ratio, figure your overall crawl ratio, and calculate your MPH offset. 32 lb-ft Ram 2011 2500/3500 6. Your other option is, if you're going with an aftermarket torque converter anyways, is to have the torque converter made with the correct offsets and mounting pads to bolt up to the stock 4. with your Dodge Ram; Hughes Performance has the transmission package to handle your needs! Muscle Car Transmission Packages are designed for modified engines, camshaft and or compression ratio increase, numerically higher differential gearing. Is it easy to do?. it comes stock with a 2. Richmond gears have already come out with new selections for your independant rear end muscle car that can help you 60 foot like never before. If we divide that 11. A new speedo gear set for Chevrolet Turbo 350 Transmission. You can also now calculate when using different transmission gear ratios, like in first gear or in overdrive. 56 and the best thing I can say about it is that it makes a good low rpm cruiser, even with 245/60s. The steepest first gear ratio of any four-speed automatic (3. Our Stage I TH400's are an upgraded build. Buy Housing Seal on eBay now! Mopar 8. This transmission is for any type high performance / heavy duty use up to 600 horse power / 450 torque using pump gasoline. For first-generation Camaros, it was only available in, and was the only automatic transmission for, big-block V8 engines. 0’s and 6000 rpm at the line. Non-stock changes are – TH400, transmission, Rochester Q-jet, headers, P22560 tires and cast iron Pontiac intake. "Numerically, the lowest you can goon a low gear ratio in a 'Glide is 1. Maybe the following example will help you make sense of this. 80 and third gear is a 1. xx gear ratios having more slip than guys running higher numerical gear ratios. Before we explore the process and our options involved with mating the Atlas-4SP to the back of the TH400, the first job is to swap out the input shaft. The new shape removes the spoiler at the back of the car and replaces it with a smooth down-sloping deck. But it won't be anywhere near calibrated for the big heavy Jeep, tires size or gear ratio that your running. The TH400 is an automatic shift, three-speed, longitudinally positioned transmission. At about 2600 dollars (depending on model) the GEAR VENDORS is not the cheapest way for you to get overdrive but is by far the best. This design would allow for both first and second gear interaction; this feature basically eliminated the need for simultaneous release and engagement of the clutch to make the 2-3 gear change. 3-Speed Transmission Low Gear Sets ATI offers Low Gear Sets for most popular 3-speed transmissions. Fill in all entries except the one you want an answer to (in green section). My son started in a camaro when he was 12 and we did that for 3 years and i got tired of all the work and money and sold everything to do with roundy round and bought a drag car and man everything has changed a bunch over the years but we are getting the swing of it again and have made all the way to the semi's once this year and my son is. 43 1st gear T-10. Gear Grinding: Is an Automatic or Manual Transmission Better for the Trail? A quick search on the Internet reveals that the preference of a manual or automatic transmission for off-road use is a matter of preference. 2nd gear--1. 70:1 yields a cruise rpm of 2,100. Multiply the two rear case gearset ratios to determine the second gear ratio of 1. In everything from heavy drag cars to off-road 4x4s to tow trucks, an RCI low gear planetary set can improve low-end power. 73 combo)? Rob. 2-Speed / 3-Speed Automatic. “Numerically, the lowest you can goon a low gear ratio in a ‘Glide is 1. 98 combined gear ratio will make even a smog motor small block Chevy feel good. 73:1 ring-and-pinion ratio and 27-inch diameter rear tires. 73 thinking i would be getting a 2. 48:1, Second gear is 1. The typical second gear in an OEM TH400 gearset is 1. Hey Guys, I was wondering if someone could shed some light on choosing a rear gear for a turbo car. 2-Speed / 3-Speed Automatic. So im going to run a 396 bigblock with a TH400 and a 28inch tall tire in my 64 chevy truck. 5 inch mt's. Hi-flow race ready front pump with larger gears for improved volume. 48 1st gear, what would be the effects of running a lower rearend ratio (to make it leave similar to a glide/3. Heav weight means greater strength. When in manual mode 1st shift is not normally split because it is to close of a ratio. Could use less gear or more motor but for mismatch parts it goes pretty good. 48 first gear ratio but TCI and others makes a special planetary gear that will change this to a 2. Coan Racing billet steel forward clutch hub. The Top 10 Off-Road Transmissions of ALL Time. gear sets for changing ratios. It does everything well: accellerate, cruise, and top end. Always calculate your gear needs when changing rear tire sizes. From complete engines, to torque converters to Monster in a Box, we've got all your HP needs covered. by George Nenadovich. 58 low gear, where our best high-horsepower Powerglides have a 1. and thus no top gear slippage when locked. 90 should be low enough for good out of the hole performance and still high enough for good mileage with the trans and top gear for highway speeds. Such a gear imposes a time-dependent kinematic constraint on the motions of the two driveshafts:. 700R4/4L60E's have a low 3. The speedo gear combination for a 2. TH400 are tough to gear for performance because the first gear is not as low as some and with a 1 to 1 final drive you lose on both ends. best et 11. 2nd gear--1. 55 etc, seems like the higher ratios are where its at for turbo cars. The first gear ratio of a TH-700R4 is 3. For the 2 speed model case, you have five available low gear ratios, three of which are available as competition grade cases. 5 comp cro moly rockers, 10"converter power glide w/ brake, 4. Classic Industries offers a wide selection of 1956 Chevrolet Truck parts, including 1956 Chevrolet Truck interior parts and soft trim, 1956 Chevrolet Truck exterior sheet metal, 1956 Chevrolet Truck moldings, 1956 Chevrolet Truck emblems, 1956 Chevrolet Truck weatherstrip and unique accessories, to nearly every nut and bolt needed for installation. BTE Two Speed TH400 Racing Transmission. the car will be driven in town 90% and raced at track 10%, fuel economy is not a concern. The 700R4 is a good transmission for a retrofit into an older car. Is the 700R4 interchangeable with the Turbo 350? and all you have to do is nab the speedo gear off of the 700r I did so with a lack of tools so I used a 2x4 and a. 11 Whats up guys , so i have a 2000 xj with C8. I Currently have a 3. Gear ratio is calculated by dividing the number of teeth on the ring gear by the number of teeth on the pinion gear. Orange = Best Overall, this is good mix of power/MPG and considered best for daily driving. Most Skylark/GS cars from 1968-72 have open (non-posi) rear axles. Bottom line: Can you mate a TH400 behind an Oldsmobile 394? Yes! Is it a good upgrade to make? Sure, although I would still lean toward adding overdrive as well. This transmission is for any type high performance / heavy duty use up to 600 horse power / 450 torque using pump gasoline. Are they really this high geared? I'm thinkin if this is true I'd like to have maybe a 3:08. Effective & Equivalent Gear Ratios Based On New and Old Tire Heights & Original Gear Enter the New Tire Height, Old Tire Height, & Original Rear Gear Ratio, Then Press 'Enter' Key Effective Ratio = (Old tire height / New tire height) * Original ratio. All PATC performance torque converters are manufactured in-house. Automatic Overdrive Transmission Swap. Info needed to spec your converter: vehicle weight. Classic Industries offers a wide selection of 1956 Chevrolet Truck parts, including 1956 Chevrolet Truck interior parts and soft trim, 1956 Chevrolet Truck exterior sheet metal, 1956 Chevrolet Truck moldings, 1956 Chevrolet Truck emblems, 1956 Chevrolet Truck weatherstrip and unique accessories, to nearly every nut and bolt needed for installation. Although some transmission installers feel that the low first-gear ratio and high second-gear ratio do not make the TH700R-4 the best racing transmission, there are quite a few adaptations you can perform to make it a race-ready drivetrain component. The New Venture Gear NV3500 at a glance. Maybe the following example will help you make sense of this. It was possible to change gear sets simply by swapping the pumpkin. It does not kick into passing gear past 50-60mph and has unreal interstate passing power. 11 gears with the T-10 4 speed but never got to drive the car. 73 Gear ratio. This trans was built with a Chevy only bolt pattern, but we have a package for Buick, Olds, Pontiac, and Cadillac people so you can enjoy the benefits of this excellent transmission. Slideshow illustrating the gear ratios achieved by a 700r4 Automatic Transmission. Each 'Pro Drive' Series torque converter will be spec'd to your combination. Are gear ratio's fixed when building 4l60e or 4l80e. Withadditional gear reductions in both first and second gear, these gear sets work well in all applications requiring an additional gear for better take-off. All they care about is smooth shifts, fuel economy and preserving the transmission from warranty claims. If you have a higher (lower #) gear than 3. Hughes Performance® HP2211EBRX valve body TH400 billet aluminum valve body reverse shift pattern (P-R-N-1-2-3) with engine braking Tech Talk A video series to explain the basics of a torque converter, how they are built, the parts inside a torque converter, and general overview of how a torque converter works. This transmission is for any type high performance / heavy duty use up to 600 horse power / 450 torque using pump gasoline. One can multiply an automatic transmission's low gear by a factor of 1. With a TH350 or a TH400, your car. IMO it IS the finest production 3 speed auto ever designed bar none. It is a good idea to replace your speedo drive clip each time the gear is removed. 3-Speed Transmission Low Gear Sets ATI offers Low Gear Sets for most popular 3-speed transmissions. Larger planetary geasets. By multiplying these three ratios you come up with a 2. 52 do the math. To figure out which gear you need, visit LatemodelRestoration. TH400 40-45 SPEEDO GEAR HOUSING with Extra Seals Turbo 400 Speedometer Sleeve.