All that for 350whp?? Leave it stock....
It takes just as much work to make a blower build make that much power...sooo, I'm missing the point here?
A built 5.3 RWD should still make more than 350WHP anyways...cast iron truck motors are making north of that easy.
http://www.carcraft.com/techarticles/1307_ls_cam_test_comparison/viewall.html
Apparently only RWD 5.3s make power.