Put the car in OD and it free revs like there is nothing there, if you put it in 1,2,3 fine except a shudder going into second it hits OD fine. I am guessing that the 2-4 band is toast, but why would it freerev when the selector is in OD? I have rebuilt these trannies and have decent knowledge about how they work, but this is stumping me. I am pretty sure this is two seperate problems. If you have an idea please help I surely appreciate it.

Overrun clutch and/or overrun sprag is gone. Time for a rebuild & all the updates (Trans-Go Performance Shift kit, Corvette servo, Borg-Warner Hi-Energy 3-4 clutches & 2-4 band, large boost valves, late overrun & low/reverse sprags, etc.). Or better yet start with a 1988-92 transmission to start with for the rebuild. Give me a call or e-mail me if I can be of help.