Rails that hold up the bed

[climberman]

I have a half ton short bed step side and I bought the rails for the bed. I even sand blasted and painted them but when are started to put them on the frame they didn't fit. The back one that goes to the tail gate measures 40 inches hole to hole and the one on my truck is 31 inches hole to hole. The same one that is in my garage is 55 inches long and the one on my truck is 50 inches long. The rest are the same thing just different measurements. They look exactly like the ones on my truck but longer. I know I just need the right ones but if I know what they go to I could sell them to someone.