ive got the comp 1.85's on mine and noticed a bit of a gain on my 4.8L .
But I bet it would feel better with some 918's and a bigger cam.
comp said it would really come into play, with the whole package.
cam, push rods and springs/w rocker arms.
didnt take long to put them in either. couple of hours is all
also gave it a good lope on the stock cam. very noticeable.
makes the truck rock back and forth a bit