I have tuned a lot of 6.7's and recently I tuned a 6.7 that had an edge with hot unlock settings on it, and when I was driving it with the edge on it I could tell right away that the edge was going to have a lot more power than a 3000Us tune. and one truck that came in for efi live that had a tune in it and the guy didn't know anything about it so when I downloaded it I saw that the US was at 4800 in the bottom right hand corner. And let me start by saying I would never want to tune one up that far due to the way it ran and it smoked so bad. so how far can these be tuned up? I know that the rule of thumb is that at 3K Us you need to start thinking about bigger nozzles but at 3K they run good but not like that one that had 4800Us obviously. the customer that had the edge with hot unlock wants that amount of power back. He towed on that setting and everything. Can the cummins take a higher pulse width then a duramax? thanks