crosswind manifold

I have one on my 360, you can see pictures at my web page, URL in sig line. I built the engine with it so I have no comparison to anything else but the engine is making approximately 370 HP with it. Hot Rod also built a low cost 350 Chevy that made over 400 HP with one so they do perform but how the compare to an Air-Gap which is arguably the best dual plane available I don't know. Until some one other than Professional Products (they say it makes more) does a back to back comparison we won't really know.