The I4 Motori diesel from the Liberty will/should bolt up to a small block trans. Ditto on a 3.7L V6 from the Liberty (and probably others). Matching the converter to the crank would be another issue, but shouldn't be much different than a new Hemi. Of course that's not the same as sneaking mileage out of a 273. W/O going to injection, it's going to be tough to maximize steady-state cruising mileage unless you REALLY sort out the steps on the rods in a TQ to give a 16-17:1 AFR at light throttle cruise. I suppose it CAN be done, but I never have heard that it HAS been done. OEM's never went there because converters don't work efficiently at those AFR's and emissions go up.
