After doing some research for my own Vortec 454, it looks like the heads are 100cc from the factory. They also have the non adjustable rocker arms, so that limits the amount you have for cams without major machine work. I am going to do a cam swap and probably a little port work, along with the pcm tune. The trucks come with factory dual exhaust into one muffler. Cut the factory one off and get some good flowing ones you like back there. Factory pipe is 2.5". Good luck with the project.if you keep the tbi, not a lot.
if you decide to let it breathe, put a set of large chamber oval port heads on it after angle milling them. try to get the combustion chamber down to 110 cc's by angle milling a set of 049 castings or 781 castings
thats very impressive. the supercharger would be the way to go if money was no object.i have a 97 vortec 454... look under sas almost done..
i have a ati procharger... k&n filter. bbk thorttle body. msd ignition, ported heads, stock cam, custom tune. stock pulleys, jba headers with high flow cats and 2.5 inch exhaust. oh and a mass air flow sensor. ngk plugs.
i dynoed at 468hp at wheels, 533 torque at wheels... have the dyno papers if u wanna see