I have access to a free 3.76 forged GM BB crank. Does any body know what GM used for alloy, and how it would compare to an Eagle 4340 forged? Eagle rates theirs at 1500hp, although they cost $800 more than free. How much of a beating can that GM crank take, for a 1000hp build up?

Tom

1053 generally but GM has made and may still make one or two better metal quality cranks like 5140 and 8640 or something like them. Sorry, I forget exact designations.

And don't forget some come nitrided and cross drilled too...

pdq67

What is the crank number?