5-ton Ram air

[FullSpecial]

Bobfj40, I do drive in the rain but not absolute downpours. Never had a problem. Expanded metal over the hole like the heater duct intake and a quasi bridge plate bolted to the headlight
guards so its not a straight shot in but certainly not restricted.

 

[simp5782]

I found this one off a Mack MR with an E6 that will work just fine as well. Donaldson # 3987862

Located a couple of Vanderhags website for a customer of mine. Even has the side vents

 

[US6x4]

Steve Saleen did some testing on his S197 mustang ram air hood scoop and they found at 70 mph you see 0.25 psi of boost. For a gas engine each pound of boost is worth 16 HP I think so that's ends up being 4 extra hp - not much.
Not sure if it's true but some big cam guys on the commercial side are saying the dual fuel mod can be worth 40 horsepower...