Of course it CAN be done if you have the tools, the skill level required, and the financial resources. Many years ago I put a 51 GMC short bed on a 74 Cadillac Sedan DeVille chassis. I first strung a center line string on both frames and then measured all mounting points on the GMC; cross wise, length wise, and distance off the floor. After the Cadillac frame was shortened and narrowed to give the right wheel base and track width the measurements from the GMC were transferred to the Cadillac frame. This included the cab mounts, bed mounts, and core support mounts. Such things as running board brackets, exhaust, shift linkage, etc all have to be fabricated as nothing off the shelf is available for orphan projects. After hundreds do the swap, ala S10 to EVERYTHING, then after market stuff is available. After all mount brackets were made three foot pieces of all-thread were locked into every mount hole in the GMC and it was lowered into place. The all-thread went through the CENTER of every hole on the Cadillac frame. ( the long all-thread is used so you can see alignment before the body/bed is down in the way of viewing). The truck was a dream to drive and ride in. The 472 engine wore out at about 200k and was replaced with a 500 which was up to around 100k when the shop burned and took with it the GMC, 2 Bikes, 2 Bucket T's, and many tools and machines.
