I was coming home the other day and I came across a 71 n600 sitting outside an auto shop. From what I can tell the car is about 90% complete, only missing the front grille, cam housing, and a few odd pieces. I'm interested in getting the it to restore. I also want to do something about the power train, possibly swapping in another engine. What would be the "easiest" swap for the most hp? I've heard of motorcycle engine swaps and d16s done to these cars.