You can match the sizes, Doninick is correct, they are 5\16-24, any hardware or Lowes\Depot should carry the, I actually found stainless bolts for around the same price as reg bolts and put them in. I think there are 3 sizes, 3-1\2, 2-1\2, and 1-1\2 depending where they go, through the cover or directly to the cover.
"Its a Ford. Nuff said. Everything else is just a glorified tonka toy"
"ASE" Certified" Parts Professional
92 F150 302 4x4 Long bed Extended cab
2001 Taurus wagon