I think I would, and you should, find out why that motor is cracking the flex plates work wrench scope
I've seen one stock 904 flex plate break all four fingers, main things going out to the converter bolt holes, and one of the original street hemi flex plates crack around one bolt from the hole to the outside edge of that flex plate shruggy

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)