Can I add one on my Stock 2003 Lb7? I do not have any extra gauges or a programmer. Thanks

With no tuner on the truck you will be fine. But... If I were you, I'd do pyro and boost gauges before you do anything to raise boost.

If you do not have a programmer the boost valve will to little to nothing for you.

i say you do it. you wont really feel what your gaining but when you get into chips and stuff its just one step down.

i was wondering the same thing as the op