Throttle foot peddle bolts

['65 chevy lover]

I did a post about this a while back but can't find the original post or I would use that. I'm looking for the ball end bolts that the throttle foot pedal mounts to on the floor. Someone gave me some info on where to find them and I did buy a couple but, (not blaming anyone here) I didn't realize that there were quite a few different sizes of these. The ones I got had the right size ball on the end, but the threaded part wasn't correct, it was 1/4" and I need 5/16". I was at Summit Racing today and they couldn't help me. They suggested LMC and, I looked online but, couldn't find any. Does anyone know where I can find these? This is holding up finishing my truck. HELP!!!!

Thanks for any help!