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GM Cars

You are looking at the PerformaBuilt Rock Crawler and Mud Crawler Series transmission.

BeastThese units are built very similar to our Pro Race units, but the focus is on durability while maintaining reasonable shift quality. These were specifically developed for commercial, heavy towing, and 4x4 vehicles. The shift on these units is designed to take the abuse and work associated with these vehicles but without the tire chirping shifts of our race and performance units.

200BandThese units feature a heavy duty pump with staked bushing, full-time lube modification, to keep the heat down, and modified lockup valve to improve the lockup converters durability so you can tow confidently in overdrive.

We use a heavy duty wide band for max hold in second and fourth gear. To compliment this we use the Corvette servo. This servo is the largest servo available from GM it will supply the clamping force needed for these heavy units but without the excessively harsh shifts associated with the aftermarket super servos.

SpragThen for Fourth (OD) we use the sonnax dual piston servo. This servo has 30 percent more holding force than the stock overdrive servo. That accompanied with the 20 percent wider band will let you tow in overdrive with confidence. Now you have near double the load capabilities of the stock transmission in overdrive.

CorvetteNext we use carbon composite frictions in the forward clutch. These frictions have an outstanding friction coefficient for max holding. This clutch has superior temperature capabilities so they don't burn easily in even the worst conditions. This is important because this clutch has to bear the load in every gear except reverse.

For the 3-4 clutch we use the ALTO heavy duty 9 friction redlined clutch set. More frictions than stock equal 30 percent more holding in this critical pack which must handle full engine load in both 3rd and 4th gears. This set has shown to be an excellent upgrade.

We next attack the weak link in the particularly heavy vehicles and vehicles used for heavy loads or 4x4 where there is constant shifting from first to second and reverse is used for more than backing out the drive way - the sun shell. To address this, we use only THE BEAST. These sun shells do not break as they are nearly twice as thick as a hardened or new OEM shell and have a welded reinforced collar. You will not have to worry about that sudden loss of reverse and 1st and 3rd gears associated with the breakage of this peace.

PumpMoving on to the planetary, both sun gears are machined with slots to increase lube flow. This is a must in these heavy duty units. A lack of lube and cooling is a killer when pulling the boat, camper or that work trailer loaded down with equipment. The Rock Crawler and Mud Crawler Series uses 4 pinion planets.

For this unit we only use the thicker K case like is used in the very high performance cars and 4x4 trucks. You won't have to worry about cracked bell housings and cases.

SonaxLastly we address the valve body. Here we perform all the updates for lube and durability, eliminate the partial lockup function in the 4L60E. This greatly extends the converter life and helps to keep everything much cooler. Next we improve the flow to the 3-4 clutch making sure it has enough supply to help ensure that it holds the load on this crucial shift. We then enlarge the apply release feeds for the lockup clutch to make it apply positively to avoid converter clutch burn up under heavy load. Finally we include a low stall heavy duty carbon composite lockup clutch torque converter.

As with all our units shipping is free in the mainland USA and there is no core charge! And since we know you need your truck handing time is 4 days or less in most instances. Shipping is to your residence or any business address with no additional charge, This unit comes with our PerformaBuilt warranty for 1 year regardless of the miles you drive! If it dies you simply return it and we get another one or the one you returned right back to you within days not weeks, Warranty is limited to repair of the transmission at our facility, we are not responsible for any other loss incurred, wages, R&I cost or any other loss.



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

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Please read our complete warranty when you decide to make your purchase so you will understand your rights and what to expect in the rare instance you may need a warranty repair.

1982 TO 1998

700r4 and 4l60e with 4.3-5.0-5.7-and
any LT1 style engine $1650.00

There is a $150 cancellation fee/processing for any order canceled before unit is shipped. No exceptions.

1998 AND UP

With 4.8 5.3 5.7 6.0 LS1 LSX LS6
series $1900.00

There is a $150 cancellation fee/processing for any order canceled before unit is shipped. No exceptions.

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.

4x4 GM units 1982 to 1997 will have either 4 or 6 bolt converter cover bolt holes these two styles will interchange. If you receive a 4 bolt and have a six bolt cover you would only use the two bolts but there is no problem with the interchagability.

Though we do try and make the right match on shifter rod length using alldata pro as a reference there are time when the information may be incorrect swapping this part over from your old unit is easy. Please if you run into this give us and call and we will send instructions or talk you through changing it. This only takes a few minutes and requires no special mechanical knowledge.