someotherguy
+1y
Don't go crazy with the plug gap, even though the factory spec probably says .060 you'll want to try something closer to .045 for the ignition system to live a nice long life. At any rate at least don't exceed the factory spec printed on the emissions label.
Uncorking the exhaust a little bit is nice on the 96-up trucks; earlier ones you have to be a little careful on whether or not it has a heated O2 sensor. The older trucks (typically 1993 and older, or 1995 and older w/standard transmission) have a non-heated O2 (single wire) and depend on exhaust heat to get them up to temp (600F) before they start reading and put the computer into closed loop mode.
Keep on top of your tire pressures, all of 'em, check the spec on the door sticker if you're running anything close to the stock type tires. If you're running bigger rims with low profile tires then the pressures are gonna obviously be different than stock dually 16's.
I'm not impressed with the high dollar "cold air intakes", these trucks have factory cold air induction just make sure you keep a clean filter in there. Don't use a K&N and if you insist on using one, be careful not to over-oil it because excess oil will contaminate your MAF sensor (1996-up.)
Gears...probably has 4.10's which are what that heavy truck needs to get moving without too much effort. You could drop it down to 3.73's which may give you slightly better MPG in the long run if you do lots of highway driving unloaded, but if you tow a lot or do a lot of city driving, it won't help or could possibly hurt MPG because the engine is working harder to move the truck.
Richard