Re: what size tires would a 67 RS have had ?
My, early '66, '67 SS/RS car came stock with D-70/14 redlines on 14" x 6", painted steel dog-dish hubcapped wheels.
I mention this b/c I think you could check the tire option box and get any of the three tire sizes on them you wanted as well as painted steel and dog-dish or full h/c's and finally Rally rims with chrome rings. (Just check the boxes)..
He, he!! And I could spin the D-70's all the way up through 2/3rd's of third gear, EASY!!!
PS., and the Salesman pointed all this out to me b/c he wanted to option my car up, but I just said, "It does come with tires and wheels, doesn't it?" And he said yes, so I said stock so I didn't have to pay any more for my car then I did.
And I then told him, I was going to put CRAGAR, deep dish, chrome reverse on it as soon as I could save the money and then get to "the City" to buy them, which I did. (Went to KCMO later and bought my Chromes)..