[Chevy454]

I wanna say I simply have it wired open, but I honestly don't remember at the moment...I'm not a betting man, but if I was, I'd put my money on the cowl induction unit any day. You can hear it drawing air while it's idling...and drawing fresh air is gonna be better than drawing engine compartment air. [I should also note, I have the air horn blocked off, so it *has* to draw fresh air.]