Hey now.
So this is a short block that I purchased from the Mopar Performance catalog about 17 years ago. I think it was advertised as “9.5 to 1” compression ratio. I put a set of rebuilt 360 heads on it and yes, I took the time to measure the head volume and deck height and all, and unfortunately found that the actual cr was really something like 9.7 to 1 at least. I put it together along with a Mopar Performance cam ( not sure of which part number, but probably a mild street Performance option) and have been driving it off and on since. Now I am finally messing around with things and trying to get the thing more dialed in, I find that if I put any timing advance in the thing more than about 3 initial, 22 total, or so, I get pinging. I just got a compression tester and measured about 180 psi , which seems to verify that my cr is a little high.
What to do..?
Bigger cam to lower cylinder pressure?
Just set this retarded timing and run it?
Try to recurve my advance to adapt to the situation?