Ok, here is the setup. Edelbrock Performer RPM Air Gap Manifold, 1 inch carb spacer with a 14x5 air cleaner element with a 1.5 inch drop base. Will a 3 or 4 inch cowl induction hood fit or will I need to go bigger? It is on an 88 camaro. Thanks, Paul Moore

 

I used to run an almost identical set-up, except with a 4" breather. I installed a 4" cowl and had/have plenty of room.
Pic of what it will look like on a bird before the new hood was made

 

hit wrong buttom here's pic

 

I do not have room for a 1'' spacer with my 3'' cowl. I am running a holley street dominator intake (about the same as a rpm non-air-gap) and a flat base 14x3 aircleaner. I have about 1/2'' clearance between my hood and cleaner. You will need a big hood.

 

I have a performer manifold with a street avenger carb 1 inch spacer and a 14x3 drop base air cleaner under a stock hood.

fits good i just had to cut the wing nut screw a bit.