Turbo sizing?

[69restomod]

Hey guys just bought a 6.0 lq4 and planning on doing a full motor build maybe using the factory 317s or switching to ls3 heads haven't decided yet and doing a single or twin turbo setup, looking for some advice on sizing thinking of a billet wheel s480 with a t4 exhaust housing and I will be running a 4l80e, I am open to all advice and information let me know what your running for headers or manifolds crossover tubing size what turbo what a/r and what kind of power numbers and drive ability your getting would also like to know cam specs! Thanks for the help guys! Pics would also be a great help