I've got a diesel conversion in the works, but it's sort of a long-term project. I've got four of the Onan/Cummins 120 HP turbo diesels that were used in UPS box vans stashed away. They're approximately the height and length of a Chevy 292, and probably a hundred pounds or so heavier. These engines are HP rated at 3,600 RPM, so they're definitely not typical low-speed torquer engines.
The really nice part about using these engines- - - -the bellhousing UPS used is the same as a late-50's Chevy V-8 truck unit, with a hydraulic clutch cylinder on the passenger's side. A SM-420, or anything else with a similar bolt pattern hooks right up, and it uses a standard 12" Chevy medium-duty clutch. The front motor mounts have the same spacing and width as a 292. UPS trucks were set up to use the 292, the Ford 300, or the Onan/Cummins interchangeably, with just a swap from diesel to gas or vice versa in the fuel tank. Whatever replacement engine was available got used as required. Most of the over-the-road trucks got the diesels, with the gas rigs used for around town. Cummins couldn't supply enough replacement engines, so UPS scrapped that erngine and retrofitted something a little more plentiful about 10 years ago. One of my friends bought a semitrailer load of them in running shape at scrap iron prices, and I ended up with a few of his leftovers. They're complete engines, crank pulley to bellhousing, and most of them still have power steering pumps mounted. The first one's going into a F-350 flatbed, and my 59 Suburban might get the next one, along with a 3/4 ton IFS to match the GMC Dana 60 rear axle that's already in there.
Jerry
