Im used to driving a No P/S, no AC car, and it may be that my 55 buick is even tougher to steer than your 66 FMX, but after a while I did get used to it. I guess I also have a nice big cumphy seat in the buick. I think the idea of too much pressure from the steering pump seems like a good possibility. I ordered the reducing valve, and will try that out, and it seems like it makes total sence that it will.