Nothing would be a bolt on fit. Fabrication would be necessary.
Not sure what year you are working on, but yes, typically all the bolt holes will be in there in the frame. When I was a kid my dad used a 4x4 Suburban frame to make a 72 Chevy pickup a 4x4. All the holes were there, he just had to cut the excess from the frame rails.
The fleetline is a passenger car model. Perhaps you mean fleetside. The Fleetside is a truck model. The 59 Chevy Fleetside short bed pickup truck has a 114 inch wheel base.
It is 117.5"
117"
no you can't the case is differnet and the tail shat is to short.
The bed size is 6.5' of a dimension of 78x9x5 would fit a Chevy 1990 pickup.
The frame on the 58 is a straight rail frame. The frame on the 70's drops in the middle. It would not be a simple bolt in application.
In short, YES.
I have seen a 1950 Chevy pickup put on a mid seventies chassis. The 66 cab on a 92 frame should be easier just measure the width length and height differences to see if any shims need to be made. ( the 50 pickup used short lengths of pipe to accommodate height differences) These were used at the mounting points of course. If you are trying to get front disc brakes a 71 or 72 front suspension should bolt right on to the 66, besides if you have the coil springs already it is the best ride you can get. If you just need a rebuild on all of your components my opinion is that the 66 has a much better frame and suspension.
No.
My sons 1962 Short Bed is 114 inches center to center
nope, but if you're good with a welder, you can put the truck cab on the bronco frame, make a short flatbed, and have a ridiculously short half-ton pickup.