Sorry about the bad pics. They are 516’s, you can partially see 516 in the last pic.
I was just curious about 2.18, never came across it before. Also was going to use them on a .030 over 383 block. Only had 906s or aluminum in the past and not familiar with
factory closed chambers. I do not think these have that step in the chamber. I’m at work now and can’t check till the morning.
Is it possible it was ground out to increase the CC’s ?
