727 Rebuild recommendations

390 cube stroker with a used unknown trans could be trouble. Or it could work fine. The only different seal is for the rear yoke. Everything else is the same.

Pull the pan and see what’s inside, is it clean or full of debris? How is the fluid? Burnt or new?

EDIT. It is ABSOLUTELY a 727. If you don’t know what you are looking at then don’t call it a 904 or 653 or anything else for that matter.

The seal? No, the special output seal is not going to be in any rebuild kit. You have to buy it separately.