im running 33x10.5s, straight piped, 3.73 stock gears, stock everything else and im getting 14-15 on average with a 45$ fill up.

you should probably tune it up and replace fluids and spark plugs and see if it helps. but regearing is the best bet.

 

I am considering doin the 8.8 ls in the rear and gearing the front to match gives me a good reason to get that pos d35 it off there plus disc brakes and i did all fluids and plus about a month ago. The guy that owned my jeep did a horrible job on maintenance

 

Have you changed your speedometer gear? I see lots of folks on here talking about mileage that don't know what their mileage is because they don't know how many miles were traveled or gallons used. You can't figure mileage without knowing how many miles and how many gallons, half a tank can be 8 or 12 gallons, that makes a huge difference.