- my trans am needs a rebuild in the tranny, ( no third or fourth gear ) i am going to rebuild it myself in a my automatics class ( i go to school at unoh for auto) and i was wondering what is the best rebuild kit and where to look, i plan on about 450-500rwhp via a ms4 cam stage 2.5 heads, so whatever can handle the power reliably im willing to do any info would be helpful, thanks