A good friend of mine built one of these a few years ago for a commuter. Took an '89 Wrangler with a worn out inline 6 and a 5-speed and put a rotary pump 4BT from a bread truck in it . Had 4" lift springs with 31's under it. Put a CJ7 front clip on it. Everything else was stock Jeep. Bought a bellhousing adapter for the Jeep transmission, used the original jeep clutch disc with the Cummins pressure plate and flywheel. Put in a hydraulic clutch setup and made his own motor mounts. Got about 27 mpg commuting 20 miles highway each day, around 60 mph. It either went to Iowa or Northern Missouri when he sold it.