contact joe at jagperformance.com when he did 02denalis trans it wouldn't go into reverse either but after pulling the trans there is one hole they tell you not to drill on certain trans, but they had to drill it for his, might give it a try it worked for 02denalis 4l80e. hope this helps later,kevin

 

Thanks for the tip v8.

Still don't have reverse, but I think we're going to take it down to Gainesville this Friday for TNT. The larger driveshaft is rubbing on the crossmember and maybe the underside of the cab. We've just gotta massage that a little bit.