They're Mopar reproductions from Wheel Vintiques. You would need to take careful measurements on your car to determine the maximum backspace (allowing for tire section width/sidewall) before the tire contacts your leaf springs, inner fender, etc. I can't say for sure since I don't have a stock axle width. (I also have offset leafs but would still have plenty of clearance if they weren't). I know there are guys here on the board who run 275 tires on a stock A-body axle and can tell you the wheel backspace required to tuck the tire into the opening without rubbing anywhere.
Another way to look at it is, 4.5" is a pretty common backspace for an 8" wheel. These would be sit .75" closer to the center of the axle. Taking sidewall bulge into consideration (and to some extent, ride height) will help determine if the tire will contact the leaf spring, inner fender, or fender lip.
That's just the register on the end of the axle.