long bed to short bed...

hey everyone. i got an 82 dually that i'm going to put a short bed on, (right now it has no bed). does anyone know how much i have to shorten the frame? it looks easy to do right in the gas tank area.. thanks in advance.

theres some info on frame dimensions between the different bedlengths amongst other things
ive seen a couple of adaptations on shortcab trucks where they allso adapted the bed itself and they took some in front and some behind the rearwheel to get the dimensions right dunno if its the same for a crewcab

You will have to take some from in front and from behind the axle. I don't know exactly how much.

Is that true on squares? If it were a shitbox, the difference is all between the cab and axle, no difference behind the axle.

Richard

I think so. Maybe I'm wrong, maybe I'll have to go over to the neighbors and measure his shorty.

Dunno but you've got me doubting myself now too! The wheelbase difference between a short and long shitbox is 14" and that's not enough difference for ahead of the axle, so there has to be a difference behind, too. Looks like I'm wrong on this one....

Richard

I'm almost positive on most trucks you have to take some from behind the axle, most have pretty centered wheel wells.

If you didn't change it both in front of and behind you would have an "Altered" Style truck.

here is a car to give you the idea.



If you shortened it all in front you would end up with a really long "tail".

If you did it all behind you would have very little "Overhang"

i have seen some where they shorten the rearend only to the size of a shortbed , this brings the rearlid realy close to the rearwheels and makes it look like a towtruck or a dumptruck
only could find this pic but it gives a good idea of wat i mean :

There is nothing wrong with doing it that way, It can even help move weight onto the front end of the vehicle with a gooseneck / 5th wheel. Or using a bumper pull it allows more tongue weight for any given amount of sag (Cause the Ball is closer to the axle so you have a shorter Lever).

I was going to build a 78 1/2 Ton and make it like an old altered drag car, but that one is shelved.