I can't speak to the 66, but on my 65 I installed American Racing wheels 17X8" in the rear with Pirelli 245/45R17 and 17X7" in front with 225/45R 17. I originally had them all the same size, but had a clearance problem in the front at the rear/bottom of the fender of the tire touching, so had to go with a more narrow wheel and shorter profile tire. (see attached Before photo). I believe the fender profile is similar on the 65 & 66, so this should work fine for you. The wheels have the standard 3/34-4" back set. I am really happy with the fit and look of my new wheels.
I'm in Central Texas so I don't know how much shipping would be for wheels and tires, I suspect quite a bit of monet. I don't like to publicly post my email but can't figure out how to PM with this "upgraded" system.I will be selling my original 14 in Ralley 1 wheels with tires Firestones 775x14 red lines 5 of them in excellent condition. they are complete.. Let me know how to contact you... Im in No. Calif...………...davyinchico