What motor to go with?

Yea you need a new trans guy.

The other problem with the 727 is the time bomb huge *** stock drum. More likely to explode compared to the smaller lighter 904 drum when that ***** is really spinning.
Funny you say that. Buddy of mine has a 70 dart w a 525 hourse 408 and had a TCI tranny blow at the strip. The drum broke while launching @ 5000 rpm pieces flew through the case up through the floor shattering his right foot. Very bad day. That kind of houre he should have had a shield.