I'm pretty sure Big was referring to 392 cranks , which they used stock , welded and offset ground etc. etc. and had a lot of success with.
The soft crank / forged connection means what ?
Forging definitely provides a denser core , but it is the surface hardness that I am referring to.
The issue was caused by ( here is my best wild assed guess ) insufficient oiling , bearing materials that were 1952 quality , leading to material embedding in the crankshafts , resulting in trenches where there once was a well machined bearing surface.....because once they started to turn , they dug in and .......I am not shitting..........050" deep trenches on the rod journals.
If it was just one , I'd go " hmmmmmm" , if I had built them all , I'd go " aw , **** ". But it was on three of them.
And ( this was in the early 80's ) some of the old timers told me to expect a lot of this. I can't pin down a year , but the 354's ( 1956 ) seemed to be
when it became less of an issue.
Comparing a 331 to a 392 is like comparing peanuts to squirrel ****. There is a definite link , but it is not that solid.