Did you use teflon tape on the threads of your sending unit (assuming you have an electric gauge/sending unit)? If so, the sending unit is not grounded, so no gauge action. Use a paste sealer or none at all.
What rear gears do you have? You didn't put anything lower (numerically) than 3.55 did you?
These guys will talk you into 3.08's if they can, so you gotta watch them :p
.
Most guys don't like the rpm's in GM trucks (from the high numerical gears), so they gear them "up" to reduce freeway R's, save fuel, engine wear,etc.........
Those stock gears are why you can out pull a F O R D any day...........F O R D's always have "tall" (low numerical) gears. Great on the freeway, but not worth a %^&* off the line or pulling/carrying a load.
Glad to see you went OD........
