As a rule of thumb, 1 point drop in compression equals a 4 percent loss in hp. Example: 400 hp at 12.1 dropped to 10.1, should be around 370 hp.
As far as pop and crackle, a cam with 108 degrees lobe centers will give you plenty of that and put most of your power in mid range which is where I
like it. Crossing plug wires will also have the same effect, although not as good
.
Thanks, Kanuck