I'll add this. I make alot of lexan boxes for hood scoops and we just cut a square hole in the cowl hood and let the lexan box hang out. prob 5 yrs ago when we made the 1st one it was sealed off on 5 sides front only open obviously. you could make a pass and I could see gas like it was floating/pulling out of the carb floating in the box abouve the carb. Drilled 4- 1/2 inch holes in the back of the scoop. Never done it again. don't ask me why. Just my experience.