The Stovebolt Site Forums The Shop Area Paint and Body Shop 1/2T bed rear is too wide ~ how to narrow?

hi guys
i'm getting close to getting the 51 running. we fire up the motor this week. I'm getting ready to fit my lumber rack and the front width of the posts fits. that measurment has not changed. when i got the free rack i measured the pockets at the front and found it would work fine. i cut the old free rack posts off and made my own. the rack is in 5 parts now, the rack and four posts that will all get bolted together. the posts get bolted into each pocket, the rear of the bed @ the pockets is about an inch+ wider than the measurement of the front post pockets. thus the rack falls short in width to fit the posts.
my question is .... HOW to fix this?

i think i need/will have to loosen all the bed bolts, fenders, bed sides to bottom in order to bring the bed sides 'in' so the posts will
fit the rack. then re-tighten everything.
Am I correct in this thought??

I am not sure how you would correct this situation by loosening bolts and repositioning parts. I am not familiar with the 53 beds so I may be wrong about the rear sill being welded. The bed sides are welded to the rear bed sill and would have to be adjusted by bending. Does the tail gate fit properly in the opening?

Are the bed sides parallel at the rear of the bed? One of the reasons that the cross sills were welded was that the back of the beds tended to pinch together or splay out at the top. The early beds didn't have welds.

Do you have a tailgate on this bed? If you are not careful the tailgate won't fit any more.

thanks for the feedback
LG ... it's a 51
my bed front is 53'' to the outside of the front pockets & a one piece sheet that gets bolted to the front bed sides w/ a long bolt
and 4 short ones ea side. this is why i ''think'' i can re-fit the rear by loosing everything. i can't find one of the
tailgate hinges that bolt to the back tail frame after we got it painted, but it's here some where. the tailgate fit (when we took
everything apart) and it's been years since the tailgate's been on the truck. we didn't take the bed frame apart,
but we took the fenders off for painting.
i'll check for parallel.
...............................

i guess i'll have to ''heavily adjust the steel posts to fit if all else fails.