Just bought the strap from Year One. However, in my infinite wisdom I have misplaced the bolt that screws into the frame and through the battery tray(for the old battery hold down). I think I took it out with a 13mm socket, but I'm not positive, and I'm getting ready to head out and pick another one up shortly. Anyone know for sure what size it is? Car is a 1994 Z28.

 

Battery hold down bolt
M8 x 1.25 x 75
13mm wrench size
p/n 11515984

 

Thank ya sir. I ended up taking my 13mm socket into the store with me...lol.