I put a rebuilt 700r4 into my 82 El Camino and I drove it for the first time today. The thing shifts fine into 2nd but will not shift into 3rd. I have adjusted the tv cable and it seems to be fine. I know that the most common problem is a burnt up 3-4 clutch pack but I was wondering if there were any other possibilities before I pull it back out and take it apart. Thanks.