GM Turbo Hydro 250, 250C, 350 & 350C Superior High Performance Transmission Shift Correction Kit This High Performance Shift Correction Kit from Superior is for High Performance transmissions like street rods and racing vehicles (cars & trucks) from 1970-79 for the GM 250, 250C, 350 & 350C. This kit can also be used to convert the 350C (lock-up) transmission back to the 350 (nonlock-up) transmission. This High Performance Shift Correction Kit will give the following results: Super positive shifts, shifts manual or automatic, prevents clutch & band failure, eliminates erratic passing gear shift, will convert a 350C to a 350 and superior for performance cars & trucks. This Shift Correction Kit will come with installation directions in English, illustrations and the drill bits that the installation will require. We also offer a regular version of this Superior Shift Correction Kit for regular, heavy duty, trailer towing and taxi applications. Please see my other listings!