Gentlemen - long time lurker, first time poster. I find my search for information often brings me to this forum... I'm dealing with an issue I need advice on. I'm running right around10.5:1 static compression on a 383 stroker, maybe slightly less. Total street motor... 64 CC aluminum Promaxx heads, block not decked, 4v relief flat tops. (Heads off, open to gasket suggestions). Switching to the GM HT383 cam - adv duration is 288/308 with LSA of 109... By my calculation I'm looking at some high overlap with this cam, but I'm out of my depth at this level of analysis. Objective: Looking to safely run on premium pump gas. Question: 1. Can I reduce timing a bit and make this happen. 2. Is this cam helping or hurting my situation? I'm calculating 80 degress of overlap, is this correct? 3. To help with torque and off the line power - increase crank advance, limit mechanical to 30 or 32 degress? Don't care to run this motor at higher RPMs 4. Anything else I'm missing? Thanks in 'advance.'