This is Hpyertech Power Programmer Plus for a 94-97 lt1. Will fit Corvette lt1 and lt4, camaro z28, trans am, formula, impala ss, lt1 caprice and buick roadmaster. With this unit you can custom tune your lt1, chance your rev limiter, turn cooling fans on earlier, change vehicles top speed limit, change speedometer for tire size, change speedometer for rear axle changes, for automatics you can change shift points and encance the firmness of the shifting. thanks~gunter $220 obo