Exactly my point...you do your research on that and can figure out how to mate a Allison to the 5.3...then ask what size twin turbos to run. Send us a picture of your truck with a piece of paper that says I'm not a troll...maybe then I will believe you.
Everyone does different sizes on the 5.3s were its so to your purpose i thought i could find better results on a customs forum website were its mostly people customizing there trucks