Rednut,
If your truck is stock, I would leave the timing where its at. Advancing the timing will move the peak torque from about 1600 rpm to the around the 1900-2000 rpm range. The engine will sound a little more "crisp" also.
You probably wouldn`t notice a major difference in the characteristics of the engine. You will notice the peak torque has moved up the rpm band though. If you plan to modify the engine to a somewhat high level, then bumping the timing makes the combination work better. Lower EGT`s, more time for a larger injector to deliver its larger slug of fuel.
Here is a good article explaining timing changes to the 5. 9 Cummins:
http://www.ecpe.vt.edu/~dfritz/technical/diesel/FAQ/timing.htm
Bill R
94 2500 SLT 4x4 5 Speed, 3. 54 LS, JRE 4" exhaust, Autometer Pyro, Boost & Water temp gauges, Bosch 215 HP injectors, Timing @ 14. 7 º, JRE Stage III #4 plate 270/675, AFC spring kit, Scotty Air, Bully Dog Propane Injection, Roadmaster Active Suspension, Optima Red Tops, Geno`s Exhaust Blanket,Espar Heater (won it!), Synthetic lubes throughout.
[This message has been edited by HEMI®Dart (edited 09-23-2000). ]