These are stock re-man vortec heads with beehive springs.
I'm currently running the Comp Cam XE262 cam but want more than this mild cam. Got the headers/exhaust with 5 speed manual tranny and 3.43 posi out back - but want more! Don't usually go over 5500 rpm. Gas mileage and idle quality doesn't matter.
Dual pattern or single pattern AND what are the advantages/dis-advantages?