The cast crank in my 73 440 has seen a bunch of 11.70 passes in a 3500 pound 65 Plymouth turning 6500 rpm and lots of street miles I just put this same engine in my 73 dart so it is going to see lots more.This engine has not been apart in over 5 years now. so i say it should be fine with what you are going to do with it.Mopar65