Truck cap compatability

Are 1st and 2nd gen beds the same size as 3rd? Are caps for all the gens compatible? I have 6.5' bed btw. Any other makes models of truck beds the same size so when I look on CL etc..

 

First gen beds are smaller than 2nd and 3rd. 2nd gens are pretty much the same size as 3rd but fitment will depend on the canopy you are looking at.

 

Not really?

First Gen are an entirely different truck really than the 2nd and 3rd gen trucks and as you say.
Oddly though I have seen later version caps that can fit on the 1st gen as long as they have a rear door that is the same height as the sides,the bed depth is much different though so full sized rear doors will not work between them.

2nd and 3rd gen tailgates are about 1 1/2" different in thickness so the 2nd gen cap may be that much shorter front to back making the rear door not work correctly or making that much gap between the cab end and cap end at the front.

Measuring carefully is the only way to be sure and yes I know this by learning it the hard way!

 

A 2nd gen cap will not fit a 3rd gen due to the tailgate. I had one on my 2010 that I hoped to use on my 2018 but it wouldn’t close.

 

There are ways to make it work usually but it is not a perfect situation for sure.
On the other hand if you have a cap that does not use the tailgate it will probably work just fine!

 

Sawzall and anything could fit. Lol