Without trying to sound redundant, here I go again.
I've got HPM drop mounts. (drop engine 3/4"
. I've got a super vic with an inch spacer. Holley carb. Drop base K&N filter. 4" filter (tall). It sticks out of the hood a good 4+ inches. You've seen pictures of my cowl induction hood. The hood is advertised as a 4", but measures a full 6" at the back. There is about 1/4" between the air cleaner and the inside of the hood.
Also, am running a Hal (QA1) crossmember, if that makes any difference...........
and on the other end of the spectrum from steve's combo is our 81 stang. With a perf rpm intake(no spacer) on stock mounts with a 2.50 inch air filter it would fit under the stock 81 hood with one of the hood braces cut out. We have a hole cut in the hood though with a 82 GT scoop. With a 3.25 inch filter it still does not stick through the hood. My guess is I can run a vic jr no spacer and the 3.25 filter with just the 82 GT scoop on the stock hood...thats the plan anyways