gm box sizes

[bobsiding]

I am looking at used toppers. I have a 2017 with a 6 1/2 foot box and can find a lot of toppers from 2013 and older trucks, but hard to find new ones without paying an arm and a leg. how much different are the box sizes? anybody with a 2013 or older.  could you measure the inside box dimensions so I could compare?    thanks guys, great site

[ewbldavis]

Frame is essentially the same, as are cab sub-structure (The same step bars on my 2015 1500 fit on my friend's 2013).

 

I would think the topper from a 2007-13 would fit. Hit Auto Anything and look up a couple - part numbers will be the same for different years if they fit.

[redwngr]

Could go to a dealer with a tap measure and on a used one check the dimensions you are concerned about.

 

Have a buddy traded body style generations and managed to move a tonneau. 

He said they are NOT the same, but he was able to make it work.  

 

Might depend on what surfaces the topper uses for location and tie down, and how fussy you are about the final look.

 

[Donstar]

I had the same question a year ago.  My research led me to buy a new color matched, correct year canopy. No regrets.

[Dnt]

I moved a Trifold cover from a SB 2009 to a SB 2014 and then actually to a 2016 SB it was a bit different bed size it seems like the cover was a bit short and maybe not quite wide enough but not that noticeable.  I would hazard a guess that a camper top (topper) would not be as forgiving on those dimensions though. 

[newdude]

The rail dimensions and width front and rear between them are different enough where some of the OEM tonneau covers don't seal up front to rear good.  We had a customer that wanted to swap a Leer shell.  We called Leer direct, they said no go. 

[sk]

A topper from a 2007-2013 can be set on top of the newer trucks but it won't fit right.  It's not just the dimensions -- the toppers for the new style trucks actually have a lip that extends down over the outside of the bed rails to keep water out and hide the black plastic edge when the topper is installed.

[ewbldavis]

Apologies - I wasn't thinking of a cap when OP said "topper".

 

A tonneau cover is probably forgiving enough to work. I would agree that a cap is likely not going to work well.

[MNorby]

I used the tonneau from my 08 on my 2015 and fit good. The 08 had a different clamp for the back to fit through the stake pocket whereas the 15 doesn't need that special clamp but it still works like normal.