Safe will depend on the truck. 94-2002, I consider 1350F to be redline, with brief spikes over that being just fine. On 2003 and up, 1450 - 1500F sustained is fine, with spikes over that being ok for brief moments.

On the injector front, we don't use any injectors on the Common Rail trucks yet (we're waiting for that butt weasel Morrison to get out of his La-Z-Boy and get us product). We do have several customers running DD injectors that they've purchased elsewhere. They've had _some_ success with the DD product, although I'm not comfortable with the injectors myself. Extrude honing is not an elegant solution to more power.

As far as 105HP extra without turbo upgrades, I dunno about that. We've seen TST equipped trucks laying down an extra 90 useable ponies with the stocker turbo, but thats empty, with a good air system, a decent exhaust and at sea level.

Rod

 

Thanks for the information Pushrod.

 

The injector vs boxes debate has been raised many times . Keep in mind a diesel flows 7 times more air compared to a gasser of comparable size . Bigger injectors will increase power but you need additional air { turbo } to keep the EGT's in check . These new engines are real favorable for injector upgrades due to ease of installation compared to older Cummins engines . These common rail beasts have electrically fired injectors compared to mechanical of past engines which entails setting the entire rack ( valve lash ) which is a real pain !! I too am leaning towards injectors down the road with a twin turbo set up and a box to control pulse ,duration ,etc . These 600 's are a hot rodders dream with the waste gate being electronically controlled ,everything is basically plug and play and these Cummins are built to take it in the lower end . The aftermarket will catch up soon I imagine and some real amazing power mods will come out . Just my 2 centavos !!