The PerformaBuilt Racing TH350 Transmission comes in two styles. The full auto/manual stick, which allows you to hold any gear to any speed and down shift at any speed, and the Full Manual Valve Body style, which allows you to start in any gear and is not restricted by governor or modulator pressure, regardless of speed or rpm. This version is intended for the track only, whereas the auto/ manual is street friendly as well. Below are the details for the build of each.

Its’ features include the following components and modifications  
(Nothing but the best):

1. The case of each unit is carefully inspected and checked for cracks and stress and cleaned in our heavy duty parts cleaners. Then the case is heated to approx 250 degrees to remove all water and to allow for additional inspection and testing. While the case is still warm, it is painted with a high gloss paint/sealant, providing an excellent finish and sealing from the elements.
2. The low reverse piston is then inspected and replaced as needed. These are a high stress point in the TH350 when used heavily for manual down shifts. Then new seals are installed and the piston is carefully installed in the case and static air tested for proper apply.
3. The rear planet set is then inspected and installed in the case followed by high energy low reverse frictions. New steel pressure plates are installed and set to ideal clearance for racing and high speed down shifts. Next the heavy duty low roller clutch and support are installed along with a case reinforcement insert.
4. The Sun shell and gear are then inspected and installed with bushings to ensure a good center clearance. This is important for high rpm driving. The front planetary is inspected and installed with the shaft support clip, and the rear end play is checked and adjusted as needed for precise tolerance.
5. The forward clutch drum is carefully cleaned and inspected. New seals and the piston are installed into drum. New Performance high energy frictions and heavy duty new steels are installed. The wave cushion plate is omitted when possible to allow for an additional friction.

6. The Direct Clutch drum is inspected, piston and seals installed into the drum, and again heavy duty high energy frictions and heavy duty steels installed. This drum is also modified to increase the apply area of the piston by 100% over the stock setup.

7. A Hardened Intermediate Clutch Race and Heavy Duty roller sprag is then installed on the Direct clutch drum and it is placed into the case. The intermediate overrun band is installed, followed by three Heavy Duty High energy intermediate frictions.
8. The Pump is inspected and bushing and/or gears replaced as needed. Seals for the intermediate piston are replaced and the return cage modified. New hardened metal sealing rings are installed on the pump shaft. The pump is then carefully aligned and installed.
9. The valve body is carefully cleaned and disassembled and all the valves checked for wear and proper movement. The shift kit is installed according to the order preference. Additionally a new adjustable modulator is installed.
10. The pan and tail housing are installed.
11. No speedometer gears are installed in these units, but they are available at additional cost, or the units can be set up for VSS (Vehicle speed sensor) for the prices shown.

These Transmissions are for the all out race enthusiast shift are very aggressive more so in the full manual version. This units is built to take a beating and will live up to the PerformaBuilt and its Race name.

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If you are purchasing a transmission without a converter please click this link for additional warranty information


All converters non lockup , all prices include shipping inside mainland United States.
No core is required!

auto/stick valve body $1375.00 CALL US
full manual valve body $1575.00
full auto/stick with speedo $1550.00
full manual with VSS $1675.00


If you have any questions feel free to give us a call 570-578-5686

The more we know about your needs, the better we can match you with the right transmission.

NOTE: All units are 30 splines, and available in either 2wd or 4x4. If you have a special application requiring a special adapter or output shaft please, contact us and we will be happy to provide it and quote a price for your special application.

NOTE: The LSX transmission has a removable bell housing which is not included with our transmission. You will need to use your original bell housing and extension housing, but the transmission will have the appropriate output shaft for your application. If you need these items they are available at additional cost. It is preferable that you use your OEM items to assure compatibility with your vehicle.




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  The unit, as with all of our units, is warranted for one year from the day
you received it. Please visit our Warranty Page.

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