I am in the process of converting to retractable seat belts and ran into a small snag.

My car car is a 72 so the "buckets" were already in place for the new retractor, however I can't figure out what bolt size goes into the firewall? There was a bolt in the parts stash that came with the kit that is close, but seems to cut new threads if I push it. I tried one of the existing bolts and same thing.

I did a search and found out the bolts at the top and bottom are M11x1.25, should this also be the same for the firewall?

It could just be overspray/gunk clogging up that hole since it has never been used, but wanted to check first.

Thanks guys!

It might be a 7/16 SAE thread. Many foreign cars were required to have SAE seat belt bolts.

Thanks Mike...that sounds about right with how close it was.