Torker II is designed for 2500-6500 rpm and is single plane manifold as you know. Now I have no expereince with this manifold, but for a "Truck" that I imagine weight over 4000 lbs, peanut port heads, and a mild cam I would be willing to be the only time that TokerManifold would perfrom better than the factory cast iron is about 4000 rpm...the peanut ports probably run out of gas at 5000 as does the cam. Stay with the factory manifold, leave well enough alone and dont change unless a dual plane for a "Shop Truck" is my opinion.