Just got home with my new toy, a '46 Ford coupe. It's got what sure looks like a 10 bolt rear and a early/mid '70s Nova front end and GM rally wheels, 15 X 8 at the rear and 15 X 7 up front. Okay, that's all good. Here's the mystery part. I popped off a couple of the hub caps and measured the bolt pattern, just thinking about changing the wheels and the bolt pattern is 5 on 4 1/2. To the best of my knowledge, GM never made anything with that bolt pattern and yes, I'm real sure. I've gone back and re-measured about 14 times and there's no question, they are 5 on 4 1/2 inches. They are NOT 5 on 4 3/4. The wheels are stamped 'GM K-1' between the bolt holes and the 8 inch ones are stamped 'AZ' by the valve stem. Haven't looked at the fronts. So. What's up with that?