70s tailgate on 80s bed issue fitting

[doughby82]

I belive the tailgate I have is 77-79. round bottom. Chevrolet script in middle and factory bans with trim on top and bottom of bans. the bed is an 86. . I replace the trunions to 70s. it fit a lot better but it get 2 or 3 inches from closing. it appears the arms are hitting tailgate or on bed. not sure how to fix this. I also remove the anti rattle clips from bed thinking that was the problem