i gave you the link for it.
you can grab an LQ4 thats for your year an swap in a stock set of heads an intake an fuel rails for about 800 at most.
thatll save you from needing the converter or having the 58x ring changed..its all up to you man.
i swapped in an 08 5.3 in place of a 94 4.3 an im tellin you now i have 5500.00 in my swap easily. its not cheap an i did everything but the wiring harness myself. i also have a 6.2 for my 08 CC with milled heads, valve job, lifter swap, cam swap, valve springs, push rods an im doing all the work myself except the head work an i have 4000 in that already.
the best of luck to you my friend. id take the cheaper way out bc the 6.2 is more money no matter how you look at it vs an 03-07 6.0 w L92 heads.
2008 GMC CCSB 6.2/6L80e swap
Gen IV 5.3/60e swap 1994 ecsb W/T