just tossing these out there as well, i'm not sure if you addressed these yet
-biggest headers you can get? (exhaust backpressure)
-cooler heat range on plugs?
-largest valves you can get in the heads?
1 5/8" tubes 2x 2.5" collectors... best other than custom steps, run axle dump axle dump exhaust 2x 2.5 into single three thru a super 44... at the track i have 12" 2.5" extentions
running street hemi plugs autolite 65's
valves are 1.7/1.44 defiantly the norm, thinking if of goin to a 1.8 intake though someday....