Tailgate Installation

[Sandemonium]

Hello,

I have looked through the many posts that explaing the tailgate installation process, however I have a different problem than most.

I have recently assembled my shortbed fleetside with new wood, a reproduction passenger side bedside and front panel. My tailgate is also a reproduction that I also got from Goodmark.

My problem is when I put a square on the passenger side bedside to the rear sill it is square. When I put a square on the drivers side bedside to the sill the bedside is leaning in about an 1/8" which causes the talgate to rub on the top of the drivers side bedside.

I have tried putting a rachet strap on the drivers side bedside and pulling it out a little farther than square and loosing all bolts on the drivers side and tightening them back up, but I have not been successful in getting the rear drivers side bedside square.

What am I missing?

Any help would be greatly appreciated.