Figuring Out Bolt Pattern
 

I was just wondering if this was an accurate way of figuring out your bolt pattern. So that for say a GM bolt pattern, the space between the two lines would be 4.75 inches?
http://www.tirerack.com/images/wheels/tech/5bolt.gif
Source: http://www.tirerack.com/wheels/tech/....jsp?techid=92

Because on my '79, the previous owner put in a 10-bolt posi rear from I don't know where, but its not your standard GM bolt pattern as 5 x 4.75 rims won't line up. Not even the rims that are currently on the car fit perfectly.

If it is a bigger pattern, it is likely 5x5.

Yes, the picture that you posted is the way to determine your bolt pattern for a 5 lug hub.

- Justin