hey guys a i got an o6 4wd long bedder with the 48re .just had it rebuilt . now when i rollinto from 4th gear without it downshifting keeping the tc locked up it vibrates like its gonna come out of the truck?? could it be the double disc tc? or drive line now? i know it didnt do it hardly at all before i had it rebuilt?? helppp also anytime i floor it to hit the passing gear it will jump up to 3500 rpms the come back to 2800 rpms and shift out like its supposed too. why does the rpms jump up to 3500? never done it before ? or maybe i never noticed it?