there the bolt that hold the flywheel to the crank. i set the wrench at 70 ft-lbs. then i tighten three bolts, the first one tighten up just fine. then i move to the second bolt which stripped out, then the third bolt i expanded the threads on it. i didn't damage the flywheel. i was thinking about tapping for a 1/2 inch bolt will size 14 threads ,but the bolt will not go through the flywheel and the medal on the outside of the crank bolt holes will be pretty thin.
I put flywheels/flexplates on w/ an impact gun, and never stripped one out. It sounds like you have the wrong sized bolt, there is no way you stripped the crank by hand!