Ok, here is my setup, I have a buddy who is upgrading his heads in his 9 second LS1 Camaro, so he is selling his ported, 806 heads, they push up to 500 rwhp so there plenty stout. Would they work well with my 5.3 thats my question? If i do go this direction if im pulling the heads i might as will take the dive and buy a fast intake as well.
2000 GMC 1500 reg cab short box 2wd with 5.3 motor, Thunder Racing TR224 on a 114 LSA 563 lift cam
Thunder Racing 7.4 pushrods
PAC 1218 single beehive valvesprings
Pace Setter Long tube headers
Cat delete
4000 Stall converter
NX 100 Shot, plate kit
true dual 3" exhaust with the Magnaflow race bullet mufflers.
HP Tuner and Wideband
3.73 gears w rear locker

 

I wouldnt put 806 heads on anything i own. You would also have to change your valve covers to perimeter bolt.