I just recently built a 1990 Chevy K1500 with a 350 5.7L and the transmission i got with it i was told was good but when i took it down the road it wouldn't shift past 2nd gear and when in reverse in motion it sounds like its winding up. I'm not sure if it has the 700r4 or the 4l60. I know the harness is a square 4 prong plug and it has over drive.