Anybody know of a tuner or chip that will work on a 03 5500? It has a duramax/allison. I tried a Hypertech and had to return it because it won't work on anything above a 3500. The truck weighs about 20000. I know its abit heavy. Its used as a service truck. Any help is appreciated.

I demo'ed the Edge's Juice on mine for a couple weeks...made a huge improvement performance wise, but I was looking for better fuel mileage and didn't get it. I returned it to the shop that installed it.. definite performance gain tho on my 03 5500 duramax/alli combo...