I have an 1989 and I can't find the bolts you are talking about, does anyone know the correct size and thread? Everything I try in there starts to go in, but stops.
Thanks

I tried the 8mm, still no luck, both sides so I don't think it's the treads in the hold down pc.

 

Same on mine. The kids getting out put their weight on the front edge and it pops it up. I bent the loop to the bolt bracket in front but back pops back up again. Maybe a big hunk of windshield tar will fix it... lol

 

I took a look at my 94 a little while ago and the pic is below. The fastener is a M8x1.25x30 hex head with captive washer. If you can't get one of those to fit the threads may be boogered up. The nut is crimped into the seat mounting bracket that is welded to the floor.

 

Thanks I'll try the 8mm