I was going to be getting an Edelbrock Performer Air Gap Intake Manifold and I know that the clearence can be an issue with Air Gaps and was wondering if anyone knew if a stock hood could handle it without having to manually modify it.

i had to get a four inch cowl

It'll fit - you'll just need to get a drop-based air cleaner housing. Air Gap dimensions are the same as the Performer RPM, and my Performer RPM fits under my hood just fine with the drop-base air cleaner housing.

I agree with the drop base. That is what I did with mine. I have no clearance issue with my LS1.

Well I am not going to be doing it for several months as I am going to be doing an engine swap to a 350(I want power vs Economy) And with that whole thing going I am going to have to see how it works. Thanks for all the info guys.