Looks like a nice project Tim!
Yea, I currently run a 9in X 2in high flow filter kit (SPE-47708), with the top side of the 273 commando air cleaner covering it. This allows it to be recessed down a bit and allows for me to run a 1/2 spacer with plenty of hood clearance on the 273.. Will be a tight fit with the dual plane intake manifold on the 408, may have to modify it a bit to make it clear the hood.
