hello, as of right now I have a standard carb with 8 foot bed, but my bed is beyond repair and my cab isn't the greatest with the previous owner hack work. my brother in law has a few 6 foot beds in very good condition, so my questions this. could I just buy an extended cab shell and swap everything over? I know I would need the last registration or title of the cab to make it legal, but would my frame mount it?

 

No the frame is different. If you look at your frame it has a kick-up behind the cab where it goes to the bed mounts. The extended cab frame has this kick-up moved back to accomodate the longer cab.

Some people have put body lifts and custom made blocks to clear the kick-up, but then you usually have some custom body work to get the bed to line up with the cab and the back wheels.

 

I already have 3 inch body lift, and fabbing up stuff isn't an issue

 

The ex cab wheelbase is 22" longer than a reg cab, a long bed is 16" longer than a short bed. A reg cab long bed is 133" wheelbase, an ex cab short bed is 139.
The only way to make the cab fit on the frame without having 6" of body lift is to channel the floor, and then you are still stuck with having to shorten the front of the bed to make it all fit. Doable, yes, worth it, that's entirely up to you, in my books, no.

 

I don't mind the fab work. we actually have 3 extra frames in the back of the garage, so worse case is extend the rear, but we have a few options I want to check out. my bed isn't usuable, but if I need to trim the 6 foot one, we have spares to chop and resize also

 

To make it fit properly, you need to add 22" between the transmission crossmember and where the frame kicks up for the rear mounts, I have gone the opposite way before, and made an ex cab a reg cab. There is a 16" section of straight frame between the front bed bolt holes and the front rear spring hangar that needs to go to make a long bed a short bed.
I personally would much rather modify the frame than chop up sheetmetal.

 

I personally don't want a 8 foot bed with the extended cab. what I could do is find a donar cab and mount it in place, then run measurements on the bed. my brother in law loves doing the sheet metal work, and having a one off bed might be worth it in the end. plus its about family time. I don't get much of that anymore

 

Since I just happen to be stripping out my 96 250 right now, here are some pictures for you:

The 16" that needs to disappear to make a long bed a short bed


Ex cab frame under the cab, tape is from the center of the trans crossmember bolt hole.


And a reg cab, measured from the same place: