I just put a set of 15x6 (used, circa 1987) on my '66 coupe. Put a set of BFG TAs on them, 225 70R15. You must use a set of 1/2" spacers and extended lug nuts. I had heard that Jegs had what I would need. I won't go into it here, but suffice it to say that I am POed at Jegs right now. Only sent me 2 spacers (a "set"),:eyerole and the extended lugs were WAY to long. I ended up finding 2 more spacers in my garage from long ago (lucky break), and got the correct length lug nuts from Discount Tire. I do love the look, though.
Rich