I have a friend who is getting his 68's wheels blasted and painted. He has some things he needs to do with his car but it is up on jackstands. I have an extra set of wheels and tires for my 71. Does anyone know if they will fit ok on his 68? I know 68 wheels were smaller that 71.
Any help would be appreciated.

They'll fit just fine. The '69 and later rally wheel is an 8-incher, while the '68 is a seven. There are no offset or wheelwell lip issues. I'm not sure about the beauty trim ring depth, but I'd have to think that there would be a difference between the seven and eight.