Hey Guys, I just bought my first Z this month and drove it 500 miles home. Runs great. I'm new to the 240Z though and don't know a ton about the engines. Mine is a series 1 with the original E31 head. I know this one is a higher compression head. What is the best octane to run on a stock motor to avoid detonation? Also, if the engine hasn't been re-built (I'm not sure if this one has) what do you do about the unleaded fuel?