I currently have a 94 lt1 mated to a 96 4l60e from my truck. Tranny is slipping real bad (140k original miles) and I am about to replace it. It looks like I am going to get a TCI 3500 stall converter and have the tranny built by a local guy. I was just going to get a 94 core (pre pwm sol) and mate that to the 94 lt1. My real concern is do I get a lockup converter or not? Is the 94 tranny lockup controlled by the computer? Right now I believe I have something wired incorrectly or my computer wasnt programmed correctly for the newer tranny. At crusing speed when it shifts into 4th there is no drop in rpms. I dunno, just throwing this out there for a tranny expert......