Got it- there is enough improvement being able to port/polish and open up the runners with this method for significant gains. I wonder then, if following theory, a header style manifold would have enough gain over a box plenum to be worth it.

 

Depends on you goals. If you building a drag racer/sled puller yup its will help. It you just daily drive the truck, its not necessary. You planning on using an aftermarket cam? How much you planning on reving-up the engine? If you want the engine to breathe over 4000 rpm's, you need to improve the air flow into the cylinders in what ever way you can. If you will driving you truck under 3000 rpm's, just do a pocket port and some port clean/smoothing. Swamp is building one heck of killer motor for his ride.I can't wait to see how it pans out on the dyno and at the track.