frame difference

[oldskool]

where are the frames different on a k-20 long box pick-up reg cab,vers k-20 sub i have a good frame for 1985 sub and would like to put my 1985 body on it . my frame is shot. i know the wheel base is different . but where tks rick

 

[Bextreme04]

where are the frames different on a k-20 long box pick-up reg cab,vers k-20 sub i have a good frame for 1985 sub and would like to put my 1985 body on it . my frame is shot. i know the wheel base is different . but where tks rick

everything frame the motor back is different. Cab mounting points are different. Mounting points for saddle tanks are not there. Rear frame shape is different.

 

[oldskool]

tks

 

[Dooley]

Apparently been done before.

 

[Rickf]

If you can salvage the cab mounts off of the p/u frame and use them on the sub's frame it should work. Use the fuel tank from the sub, make a flat bed and your good to go.

 

[bucket]

A crew cab will bolt onto a Suburban frame, but using a regular cab will require some work.

 

[oldskool]

tks for the input , just thinking ? suburban frame, cut the suburban body 1 foot behind the front doors. use the back of a pick-up cab for rear window. cut a long box stepside box to fit. body lift to get the body lines to work ? i have the shop, tools, time any input tks rick

 

[CheemsK1500]

tks for the input , just thinking ? suburban frame, cut the suburban body 1 foot behind the front doors. use the back of a pick-up cab for rear window. cut a long box stepside box to fit. body lift to get the body lines to work ? i have the shop, tools, time any input tks rick

A long bed stepside box is pretty rare during the 73-87 years, you'd be looking a long time for one. I'd suggest either stretching the frame to match a pickup wheelbase or just building a custom flat bed for the Suburban frame.

 

[CheemsK1500]

With a frame stretch and lots of body work, you could try to recreate this monstrosity:

 

[AyWoSch Motors]

I was told my the dad of a friend that a suburban and a single cab longbed are the same, completely swappable except the rear where the bumper bolts.
I'm guessing buy reading this that that isn't true?

 

[CheemsK1500]

I was told my the dad of a friend that a suburban and a single cab longbed are the same, completely swappable except the rear where the bumper bolts.
I'm guessing buy reading this that that isn't true?

There's about a 2 inch difference in wheel base length (The Suburban is shorter) that prevents an 8 foot bed from fitting correctly. I think the frame contours are little different towards the rear as well. Like others said here, things like cab and fuel tank mounts are also unique to their corresponding trucks.