Iron head 452's from a 77. Standard stroke for big block. Hughes 2832 cam, standard rockers. Should be 10:1 base upon piston specifications. Now the pistons where suppose to be at "0" deck when purchased but machinist had to trim deck .020 so they stick up above the deck .020. Once again 52 degrees max. Now one other thing, the MP distributor has a vaccum advance in its pod. I tried to back it off ccw as Prof. Erhenburg says to do. It didn't change a thing. I backed it off three full turns without a change. Not sure that is normal.