I can only speak from experience- parents had an 85 coupe de ville with the 4.1. Its a massive turd. You could do a bunch of stuff to it, but naturally aspirated its a dump box, and are infamous for rear main leaks.
Yeah, no power, I think 150hp. That is why I was looking for even 5hp. Car & engine only have 60K, so far, so good. I like it (I know it is love it, or hate it) and may swap the engine when I have more energy. It looks like this one, except later alloy wheels. I just stole the picture, no idea about the other cars.
