Had some work done to my 5.3l gettin ready to swap it
Into my 99 1500 and take out the 4.8l
Need better advice on tuning for the the 5.3

Chevrolet performance ls6 valve springs
Come cam lsx adjustable timing chain and gears
Comp cam hydraulic roller lifters
Come cam XR259HR-12 206/212 dur and 515.522 lift
Full engine rebuild

 

There's a tuning guide on here done by Krambo. Very good resource. Search for it.

hptuners forum has great info as well