You could chart a new course in your project and do like GM did with the Cadilac so many years ago. Use the engine, controlled by a computer and cut back unused cylinders.
I don't know how many times I can change course before everyone loses faith in me. But I want to get input on just one more idea...
I have a 1991 Jeep Cherokee/ XJ, wrecked. I bought it for parts to build an offroad buggy later on down the road (low priority project, probably would never get around to it anyway). The jeep has a 4.0L inline 6cyl and 4sp automatic transmission. I previously had not considered using it, or anything with an auto tranny, because I thought that the fluid coupling of the torque converter would introduce some mininal amount of slip in each gear, depending on load (which would make it impossible to "lock in" at 60Hz). I had a talk earlier this evening with a mechanic friend of mine and he said that's not the case. He said once you get past the stall RPM of the torque converter, the engine can be considered directly coupled to the transmission. And even if there were some slip (which would indicate transmission problems), if using the cruise control, it should adjust engine RPMs to maintain constant output of the transmission tailshaft.
So now I'm thinking it might make some sense to open up the rear hatch, pull the rear seats out, and shove an 1800lb generator head in there. I could disconnect the driveshaft from the rear diff, cut a hole in the floor, and bring the driveshaft up and couple it to the generator head.
I would have a "Jeeperator" capable of >100kW in short bursts, already sitting on 4 wheels and with the minor addition of a jeep tow hitch (as seen on every 3rd motor home on the freeway) it could be a trailered unit. It should have decent fuel consumption since it will probably stay in 4th gear at 1350 engine RPM most of the time, and downshift as needed, all the way to 1st gear @ 5040 RPM.
