I bought a Bravada from my friend after it had been sitting for 6 or 8 months. When he drove it last the trans was fine. I put in a 355 TPI and the trans would shift very sluggishly into 2nd and 3rd and once it got into 3rd if you gave it gas it just slipped. It did this at light throttle so it's not like the engine has too much power for this trans.

One thing that caught my attention is that when I was bolting the converter to the flexplate, the coverter wouldn't sit flush up against it, I had to put two washers between the flexplate and coverter to keep the coverter from flexing under compression from the bolts. When I pulled the trans back out because of it slipping, I realized that the coverter didn't sit flush just because there was some rust on the snout and it didn't fit into the crank but now it sits flush just fine. Is it possible that because the coverter was sitting about 3/16" too far back that it contributed to the slipping problem? Any other suggestions for what the problem may be? When I drained the fluid it was pretty dark and smelled burned.