The stock 4t65eHD is a strong transmission in stock form, but has its limitations and flaws. Our standard rebuild comes with all new clutches, all new electronics and solenoids, MMS shift kit, hardened 4th clutch shaft, and valvebody shift improver kit - making the 4t65eHD perform better and more relaible than even a brand new factory unit. The limit of out standard rebuilt transmission is right around 300whp, which is where the stock input shaft has issues. A stock supercharged 3800 car makes about 190whp in stock form, so if you add over 100whp to it, you're going to need a performance input shaft. The next limitation after that is the stock gear set, which is good until around 350whp. The bottom line is we can build your transmission to withstand whatever kind of power levels you're looking to support. We've even built transmissions for street cars making over 600whp.
There is a $500 refundable core charge on transmissions. Core transmissions can have normal wear and tear, worn on clutches, bad electronics, worn input shafts, worn 4th clutch shafts, broken accumulator springs, and many other common failures, however cores must have a good or atleast re-buildable valvebody and channel plate, and a differential in acceptable condition as these parts are not billed for in the transmission cost, and are to be re-used. Core transmissions that do not meet this criteria will have the replacement part value deducted from the core return price that is refunded to the customer.