Tire Size for 5.5 small bolt rally wheels on 64 Valiant 200

Mine are on a '66 Barracuda and a '66 Valiant Conv. I also have 215/70/14's on a '66 Barracuda, and some 235/60/14's on a '66 Barracuda. They all have enough clearance so far, but, I don't use them for slalom racing or off road, so, haven't tested them to the extreme. I can get 9/28/14" slicks on the back if I trim just a little off the wheel opening lip edge to keep from cutting the sidewall. This is on some slotted mags, stock 8 3/4 rear, and stock spring location.
lol Yeah, all I want is spirited cruising at best. I won't be rollin the tires over on the sidewalls. lol Thanks for the input.