bop

Chaps, I need a decent TH400 with the BOP (non-Chevy) bolt pattern. I believe there are two lengths for these and I need the longer one. Maybe there are more than 2 lengths, in which case I could be stuck. Box needs to be leak-free, and working order so I can bolt in and drive.

I have one of these that needs rebuilding, would like to have a go myself as though i've built hundreds of engines manual boxes and back axles I've never built an autobox, apparently it's in good order generally just slips under load.. Where is the best place to get a rebuild kit from and what...