Does anybody know if you use Mr. Gasket Stackable MLS Head Gasket how much you can lower the compression. I have changed out the pistons on my d16z and now I am running 11:1. I need to lower the compression so I can run 93 octane fuel with out having to dump in octane booster. I have already pulled the timing back with an adjustable cam gear but the car is still knocking on 93 octane. Car is a daily driver so I can't afford to keep putting in octane booster.