i have a 91 caprice with the lo3 tpi and i want a 5.7 tbi to put in it what car or truck can i get the 5.7 out of that would have the most hp and torque stock. I also want to put a posi on the car to what car can i switch it with that has good highway and street drivability.

I think you have your numbers backwards, LO3 is a 5.0TBI and you probably want a 5.7 TPI

i know i have the lo3 5.0 i want a 5.7 tbi not tpi

I'd suggest the tbi forums