On the mustangs the input shaft is 2 piece and weak. In OD the convertor locks up to eliminate slipping and what not. HP is very limited while in OD. Unless you spend the bucks for a Lentech AOD, or at least a tremec 3550 5spd you will kill either behind a 351w. Can it be done? yes, will it last? depends. On the cheap a c-4 will be longest lasting bang for the buck. An AOD with a good shift kit will also work but for how long?. T-5 can survive too. I say go cheap and use what you got until it breaks.