I think that using the John Deere generator would be problematic because of the voltage output. If its a 12v or 24v system, you would generate less than 1kw or 2kw respectively.
At least 10kw is needed to get a passenger car down the road at 55 mph. Additionally, changing DC voltage is practically impossible at these high amperages.
The local JY just quoted me $300 for an L24 engine, and $450 for the entire car
I figure we'll need the block, wire harness, ECU, gauge cluster, and fuel delivery system. It will probably be a while before this project gets rolling... I've got a dead Zap Xebra I have to get working and out of the garage.
~Jimbo