I agree with Pwtr, Fast intake and any TB bigger than a 90/92 is a waste because it will hurt low end which is more important in a truck that keeps the rpm below 6500. For example a buddy makes well into 1,200hp with a standard ls2 90mm TB, his 102 and 105 had tuning issues. I think
@randeez even runs a 90mm LS2.
Ported heads/good heads on the other hand are always good within reason. No point in getting PRC 260cc heads for a 5.3 but a set of worked 862s/243s or a nice after market head like a PRC 220 would help both NA and boosted. Most important thing is get a head that compliments the cam.
Best place I've found to learn this stuff for free is Richard Holdner on youtube. Even if you just skip to the parts that it shows dyno graph comparisons.