Does anyone know the thread pitch of the stock seat belt bolt that mounts the lower bracket of the seat belt to the chassis?

I'm talking about this bolt:



I want to find an eye bolt that will fit the stock location for my harness install. I believe G-Force eye bolts are advertised as 1/2", Schroth are 7/16", and one Sparco 22mm eye bolt I saw was M12x1.25. I searched and found a thread from 2004 that said Sparco eye bolts fit in the stock location, but I was hoping someone knew the correct thread pitch.

Sparco is 20 min away, so I think I'll go there tomorrow to see if they have a bolt that fits.

 

I made some calls. It Sparco, G-Force, and Schroth all use 7/16" SAE (fine) thread pitches. Sparco doesn't have them in stock, nor do they have a retail store, so I have not been able to see if these fit in the stock location. I think I will take the stock bolt out and test it out at the hardware store.

Edit: The bolts are 7/16-20