EFI Live tune
check spark
check fuel WOT
Check fuel trims driving around and smooth them out
tweak things....
I would not and do not suggest just using a tune online. If he did a good job with the 5.3L I would go ahead and let him do your car. That GMC has damn near the same tables as that Camaro and its the same way of tuning it. Its just a gasoline motor with spark versus a diesel motor ( yeh, i know I'm over simplifying it)


