My dad bought a 06 LBZ back in January and just last weekend we put a Diamond Eye 4 inch turbo back exhaust on it and I've loaded a couple different tunes in it with efi live. The current tune is supposed to be around 100 hp over stock and it feels like it. The power comes on very hard and fast from 3/4 throttle on but it just feels too extreme for an otherwise stock truck. I've been reading and timing seems to come up a lot. From what I'm gathering by reading and looking at the timing on various tunes diesels seem to run the low timing at low load and increase the timing at higher load and engine speed. This seems to be the exact opposite of a gas engine which I'm used to dealing with. I know on a gas engine for the most part in stock form you can gain pretty significant power and economy just by getting the timing right and the fuel otherwise needs next to no changing. Would the same concept apply to a diesel? Optimize the timing and leave the turbo and fuel settings alone? We really aren't needing more power just more economy. Can timing be altered without having to mess with boost and fuel?