DaveR455

Hi all, I know this is an old thread--but it is right on point for my question. I recently got some early 1980s 15x7 rally rims in good shape, and I'd like to put some bigger tires on them for my '71 Riv. I was thinking something like 255/70R15 in the rear and 235/70R15 in the front, to give it a nice stance. I've got lots of room in the wheel wells (based on the 215/75R15s that are on my current 6" rims). Any thoughts on how big I can go with the 7" rims? I would like to get redlines and love the look of the DBs. I greatly appreciate any and all responses. Thanks very much. Dave