You have to figure out your DCR (dynamic compression ratio). You have to know your cam specs to figure it--go to the Keith Black website and use their calculator. As a guideline, 8.0 is maximum for iron heads, 8.5 is maximum for aluminum heads. It is not possible to tell from static compression ratio whether your compression is too high because cams bleed off specific amounts of compression based on the opening and closing of the valves. Essentially, the bigger the cam, the more static compression you can run.