Built a pair of 454's with 420 mega blowers 8.0 compression with 6lbs boost. Aluminum 315 cc heads. Should end up with static compression around 11.0. General info on plugs are as follows: Colder plugs work best in supercharged applications and warmer plugs in general performance uses. Most cast iron cylinder heads use tapered spark plug while most aluminum heads use a gasket style plug. What is a good specific plug for this application?

Assuming the heads are macined for a typical 14mm thread and .750” reach plug I would probably start with something like a NGK BKR7E :
here are it’s specs:
https://www.ngk.com/ngk-4644-bkr7e-v-power-spark-plug

what pulleys size are you using to get to your 6 lbs

tks