I have G30 van exhaust manifolds with the driver side that has a rear exit that has a nice 45 ish slope back. I had wanted to use it similer to how your routing up front, but im still running a machanical fuel pump... If you put somthing like that in there it would save a lot of exhaust tube, and heat... And still accomplish the same thing... At most you'd have to rework that frame bracket for the motor mount, but prolly not.... Also they take a gasket/bisket insert w/ no heat riser flapper thing... I ended up runing ram horns for better fitment, but if your interested in the ones i have PM me... -mike