Yeah, if you go onto Diablo's forum, there are a lot of threads that will help out to customize the performance tune. They are very good about replying quickly and solving all of your problems or questions. Go to the GM Gas forum and Mike will help you out.

 

Yes. Of the shelf tunes are universal, but custom tunes can make the most hp for that particular motor, in your particular area (elevation and overall temperature). They can simply "dial it in" better and squeeze more out of it. Not all 5.3s and 4.8s are 100% exactly alike so they make the shelf tunes a little milder than they could be. If you have mods done to your engine a "dialed in" or custom tune is a must.

 

Yeah, even with the little stuff that I did, I had to adjust the injector slope to make if more rich. It was running a tad lean from checking the LTFT's. I only had to move it 1%, but that got me to the numbers I needed to be at. I am slowly adjusting the WOT Timing to see how much I can really get out of it. So far, I upped it 10% (2 degrees or so) and there is no knock retard. I am going to give it a couple days and advance it some more.