I swapped in a 03 4.3 with a 4l60e and the AA hookup to twin yota cases and it works good with good power. I pulled my 22re out of my 92 pickup cuz it didnt have the power i wanted to spin 37s. with the 5.3 you will have a tight engine compartment and might have to cut firewall or radiator supports. I had to switch to electric fans and an aluminum radiator for the 4.3.