Fact: You want it to run strong on 91 (fast curve). You have little/no quench. (1) pick the cam YOU want (2) Pick a head gasket(s) that will get the SCR down to where the DCR will not ping on 91 & let you run a fast curve. (3) dial in the dist. Taking some CC's out of the heads will let you not have to go so thick on the gaskets as either way you will have to deal with thicker intake gaskets likely required to make everything line up. Just me if the pistons are high enough to where I could get quench with the right thin gasket I'd mill some reliefs in the piston decks & the heads to lower the SCR then rebalance the crank or possibly heavier pins to make up for what you took off the pistons & as said you can take a "significant" amount off of the pistons before rebalancing is required especially with them being aluminum. If the piston deck is .150" or thicker you are OK. IMNHO no way is quench by itself going to take care of the SCR being that high with crap gas plus you dont have the cam you'd like. I dont think you want to go back into the shortblock so dont take my ramblings in the 2nd half of this serious