89 seat bolt size

[89GMCJOHN]

I have looked and can find no definitive answer....I have an 89 single cab with the split bench seat ...anybody know what size the bolts are that hold the seats to the floor ? I need to get 4 that are missing from my seats Thanks in advance......

 

[sewlow]

Head size = 15mm.
Wrecker 'pocket parts'.
Good thing the P-n-P here doesn't make people walk across a scale when entering & then exiting! Lol!

 

[s98gmc]

Head size = 15mm.
Wrecker 'pocket parts'.
Good thing the P-n-P here doesn't make people walk across a scale when entering & then exiting! Lol!

I have a few extra seat belt bolts obtained the same way.