The Stovebolt Site Forums The Parking Lot Big Bolts 8 to 10 lug adapter specs

Good afternoon! I am currently working on a 1966 Chevy C60 project. Putting the cab on a 1998 GMC Savana 3500 dually chassis. I would like to go from the 8 lug pattern to a 10 lug to be able to run 22.5" alcoa wheels on it.

I work for a machine shop that could make me adapters if I knew what dimensions the adapter needs to be. So far I have the center bore size, both 8 and 10 lug pattern size and thickness. I just need to know what the outer bore size should be.

Anyone know where I would find this information? I've come across several different styles of these adapters but haven't been able to find the dimension specs.

Thanks in advance!