The ally has to come out should I do anything extra

[Jackanapes]

I would say that it has seen hard use as a work truck for an oil well servicing company. (Key Energy Services)

Yet that does not mean that any performance programming or other power upgrades have been done.

Thank you so much for your response and I will discuss these things with my mechanic.

I would in future hope to up the HP a little in the interest of better fuel economy as the truck is intended for hauling an RV trailer. 50 to 100 more horse power with the right gadget I should think... Would that be okay?

[More Power]

At least for the LB7/LLY, my experience has been that the 50-100 extra hp improves towing fuel economy, in large part because the engine has the power to remain in OD more often while towing in hilly country. Simply put, kicking down and running at higher engine speeds for the time it takes to pull that hill burns more fuel. There may be some additional benefits in injection timing and fuel/boost mapping, but I think the biggest benefit is having just enough extra power to remain in OD. The performance module setting I use most while towing adds an additional 70-hp (it's been dyno'ed a few times).

I also found that with the additional power, EGTs are lower because the engine is running at a lower RPM while pulling hills with a trailer. This is so because factory turbos are more efficient and turbine drive pressures are lower at lower RPMs (in the 2000-2400 RPM range).

Jim