i to have a 2010 5.3 and noticed that the more i mess with the adjustable peramiters i loose power big time. i think its because when you install stock tunes it has already tweeked timing.. i think. as i gain more and more upgrades the chip helps more i think. especially on 91 octane. probly close ...

How and where do i get a custom tune for my 5.3? Ive tried messing around with spark and fuel adjustments but itnl ends up having less power. Notnsure what to set things to to get the full hp and tq out of my trinity T1000