The RPM air-gap intake is the latest/greatest thing. Makes HP by keeping the carb. cooler.

If it's an auto tranny w/low stall converter I'd run a 600 vacuum secondary Holley (1850). If it's stick or a high-stall I'd run a 650 double pumper.

Your HEI has no provisions for timing advance but can be converted. I'd buy a re-man for a pre-80 chevy V-8 and use the computer distributor for a core.'course, more spent in that area the more you get, kinda.