I had a 67 318 I don't know the compression I didn't know all the stuff that I do now to figure it out but it was stout little engine I "rebuilt" it and put 360 heads on it and a 340 intake (same heads and intake thsts on my 360 now) and I was surprised that the pistons were dang near zero deck. They where factory pistons I believe but they were not in the hole like the 318s from the 80s ive worked on. I wish I would have kept that short block when I sold my barracuda I pulled the heads and intake off and put the original heads and 2bbl intake back on. Id like to have that engine now it came out of a 67 belvedere. I'd like to have that car now. It was a pretty solid four door in the junkyard I wish I would have bought the whole car