Well unfortunately 4.8L and fuel economy don't really ever get mentioned in the same sentence... Stock they run around the 16/100k. Up to 20+/100k.
Gas may save you a bit of coin, bit economy is worse again.
What gas system type is it?
If your cruzing with heavy loads then first thing I'd suggest a suspension upgrade. Lift if if you wish, 2" is a good all round lift with minimal outlay.
You can look at bar work, lights, engine mods... How deep are your pockets?
Kallen Westbrook
Owner of
Westy's Accessories