Spare Tire Bed Holes + Mystery Holes

[72FamilyBlazer]

1) Doing a forum search, I've found the spare tire bolts necessary are a 7/16 fine thread. upon inspecting the bed to see the holes I noticed the bottom right corner is significantly larger than the rest and does not have threads for the bolt to enter. Has this been drilled out?


2) Also, there's mystery holes in a peculiar pattern on the floor. Anyone know what these are for? They're quite small.

3) Lastly, there's two bolts on the right side of the bed floor. They look like they held something down, but I can't seem to find any pics of anything that would go in that area. Is this a PO add-on/alteration? Thanks all!

[Tuff Gong]

I'm guessing the holes in the last two pictures are something the previous owner added. My truck bed has about 20 extra holes in it for some reason.

[Blazerowner]

Not sure on size but someone may have drilled them. Bottom picture might be the holes for the bracket that holds the side panels. You could always reweld in some cage nuts.

[1rippen6]

I'm guessing the holes in the 2nd picture are for the jack hold down bracket.