[briannutter]

Just bought it and and gas mileage is abysmal, yet I still love driving the thing. I'd like to get some opinions from guys that have made some sizable gains without extensive aero mods. Here's where I am right now:

I can't top it off yet to do a mileage test due to deteriorated fuel hoses, but I'll have that fixed next week. So far it's looking to be 10-12mpg with it's original 360 2bbl, turbo 400, full time 4wd quadra trac, etc.

Engine: I ordered an Edelbrock airgap performer rpm, a new Holley demon 625 carb (1 3/8 primaries versus the 1 9/16 primaries on the original motorcraft 2100). I chopped off the ancient factory muffler and went with a 2.250 i.d. straight through muffler on the original 2.500 o.d. exhaust. I checked the factory advance curve and it's conservative for a jeep that doesn't tow very often. I've got a new HEI for it and I'll correct the curve. We'll chassis dyno it with the center diff locked and prop shaft disconnected to get some additional data.

The next thing is going to tee-off some purists, but I'm putting the original 4wd system on the shelf for now. I ordered up an .78 o.d. 5 speed AX15 trans from a 2wd 4.0 Cherokee. Conversion parts are about $1000 plus a centered differential rear axle (3.54 to 3.08 gears) and drive shaft. Removing the front stub axles so the internals aren't moving. I'll build a fuel cell behind the rear axle that cleans up the aero coming off the axle. I can block off part of the grill opening and do some panels underneath to clean up the aero further. Cruise rpm in the mid 60mph range drops from 2800 to 2000 rpm. Net weight reduction is 175 lbs and acceleration should be much better when it's required. Zero toe alignment and LRR tires when the BFG's are shot.

I don't know that I can achieve 25mpg without EFI, but I'm at least hoping for 20. Even at that with the mileage I drive, my $2600 investment only takes a year to pay itself off.

Any thoughts (other than buying a diesel rabbit)?