I have a '93 w350. If all I'm concerned with is mpg's, what do I do? Also, I have the rebuilt 518 w/ lockup.

 

Advance the timing and make sure the tires are inflated.

 

Tires can make a difference - highway tread is better than all terrain which would be better than mud tires (think rolling resistance). Also the narrower the better - less contact with pavement. Gearing makes a difference, 3.54 are better than 4.10s for mileage. If you don't have one, install a bed cover or canopy - an open bed with tailgate up can create alot of drag. Lumber racks are definately not "aero" and will reduce fuel mileage. Weight reduction, don't carry what you don't need. Aftermarket torque converter is said to good for 1-2 mpg. I don't know how much of a difference these things will make but it will be some. How about one of those Charger Daytona nose extensions!

 

This was an interesting study.
http://www.cartalk.com/content/colum...ctober/05.html

 

Welcome to the DTR BCRick! I had read on another site about that. They also stated the wing on the late model half tons that isn't on the 3/4 and 1 tons tailgate is for meeting EPA fuel milage requirements.