Thanks a lot man.. I appreciate all the answers. More...

How does retarding ignition timing help to reduce detonation? Logically, you would think that if the mixture is going to detonate, it would do so at the point of greatest compression (exact TDC) .. so why does moving the spark later after TDC reduce detonation?

Regarding the valve timing: Understaning that since it's a SOHC, and I can't change the intake/exhaust timing relative to eachother, what would be the effects of advancing or retarding valve timing? I understand what you were saying about the benefits of opening the intake valves earlier .. however that also means you're closing them earlier, and opening the exhaust valves earlier too. What overall effect does this have versus opening everything later? I understand that a dyno is really the only way to properly tell, but are there any general rules of thumb?