..... I forget the #'s but a phone call to Crower will get you up to speed if you are seriously interested.
From what I have gathered all the 3.74" cranks that have failed have been oem cranks from ford. Have not heard of any of the china cranks failing yet? Possibly the metallurgy of the china units are different...? Wonder if anyone has weighed a china piece against an oe unit.
On another note my chine 3.74" crank has held up to turbo'd 20psi with a 35hp shot of nitrous. My 4r70w not so much