I can answer your question's on this one , here is a pic of my 67 with 14 X 6 rally wheel's all the way around ,
mine are original GM wheel's code XG is the best one for use with disk brakes the XG code wheel's have a lip on the back of them that allow's them to clear the disk brake's , code XN wheel's will fit and work wth drum brake's , I don't know what to tell you as far as ordering repro wheel's
I guess just call the company and ask , MY PERSONAL ADVISE is to buy used original GM wheel's off ebay they are alway's on there and cheap ! just do a search type in XG rally , anyway my wheel's don't scrub and sit in the wheelwell nice ! in the front and rear here is a couple of pic's ,,,,,, good luck ,,,,,,
I've got more pic's of other angle's if you need to see more ,,,