Carb Intake Combo, Whats Needed?

i just picked up a new air gap for my 360. i've only heard good things about them exept for a long warm up time when its cold out. havnt put it on yet but i guess well see what it does. i was able to pick a new one off ebay for $190 shipped. ive been looking for them for a long time and thats the cheapest i found. still a few bucks saved there is a few more for the rest of the engine. as for the carb, i am running a 650 holley vac secondary for street use. for the 318 i would probably get a 600. all depends on your build though.