58 Chevy Long bed want to make into a Short Bed!

Where is the chassis cut and welded, and how much?

Shorten the drive shaft.

What else am I missing to do this job. This truck is a one owner
truck and has been in dry storage for 25+ years here in the So. West desert and is a perfect project, except for the long bed.
Has anyone done this?

I'm sure some one has. try the www.efabman.com I think he shows a frame shortening process. as for how much i'm not sure but the short one has a wheel base of 114".

there are 2 different length longbeds. how long is yours?

Are we talking longer than 8 feet!!!
I am sure it is just 8 feet but I will measure it too be sure.

Yup, it is 8 foot bed.
I looked at EB the fab man and all he has is videos to sell!
Is he the only one who has shortned a long bed to a short bed!

I shortened a longbed. The longbed I think is 123 1/4" wheelbase. The Shortbox is 114" wheelbase. I removed 9 3/8"" from the frame behind the cab and slid frame together. I had a local fab shop bend up a 2' long piece of u shaped chanel (I took the piece of frame I cut out so they could bend the piece to fit snugly inside the old framerail). Then I cut it in half and put one piece on the inside of each framerail and clamped with several weld clamps. I should have noted that before I cut the frame, I measured between 2 holes that would not be removed when I cut out the 9 3/8" of old frame rail. Then when I shoved the frame together 9 1/4", I used those 2 holes to measure by to make sure each side was 9 1/4" shorter. With that being done, I used a long straight edge to insure the frame was straight in every direction. Once that was done I laid out and drilled 4 holes on each side of the weld joint (one on top of the frame, one on the bottom of the frame, and 2 on the side of the frame. Using grade 8 bolts, nuts and lock washers, tighten everything up and remove all the clamps. Recheck and remeasure straightness and dimesions from side to side. If you cut right there should be a 1/8" gap between framerails for the weld. This will allow you to weld all 3 pieces together for a strong joint. After the wheelbase procedure is done, you will have to cut the back of the frame off (where the rear bumper mounts). Can't remember how much, but just measure off of the hole for the front box mount to the rear of the box. Compare the difference between what you have and the actual #'s from the short box itself. ANy of this help?

I believe you may have to remove the rear crossmember as well, or maybe move it ahead.

Thank You, that spells it out, I knew someone had too have done this operation. That should make the job easier than changing the frame!!

Actually I brought a shortbed frame for 100 bucks made life much easier.