Anyone know where to get BB head bolts with the correct head size? I have a 1969 427/425 that has ARP head bolts with a ˝ socket head size that I want to replace with original head bolts. The parts guy at my local Chevy dealer said the only ones he can get have a 9/16 head. I think the originals were 5/8 or 11/16. I tried a few places but they all said they couldn’t get the larger head originals.