ok. been down this road myself. the 451 stroker I built, I used a 440 crank and had it turned down. it ended up being from a manual trans vehicle. The pilot bearing will need to be pulled out. You wont use one for the auto converter. You'll need to get the correct flexplate for the year/model of auto transmission you have. this will properly space the flex plate and the crank end, thus allowing them to go together