from the cam card, i see you calculated dynamic compression ratio (dcr) from .050 duration numbers . you cannot do that. you need to use advertised numbers. from the advertised duration and max lift degrees (both on the intake) , i calculate the intake closing point is 70* abdc ( 109 + 282/2 - 180) . using this (70*) and the other engine specs you stated, gives me the following results : static cr is 9.35:1, dcr is 7.13:1 , and cranking pressure is 137 psi, which, in my book , will be fine with 91 octane. in my opinion, you will need as much as 37-38* timing