Changing from standard cab to crew cab

[Freebird41]

I have a 1979 chevy 4wd 1/2 ton LWD. Has anyone ever changed from a standard cab to a crew cab? I am wanting to try to do this if it is NOT very complicated. My thoughts are to change the cabs then fabricate a flat bed behind the crew cab. I already have the crew cab. Any help and advice is appreciated.
Freebird41

[N2TRUX]

I think it too big of a job. Why don't you just give me the crewcab instead.... j/k

Do you just have the cab, or complete frame? You would be much better off putting the 4wd running gear under the crewcab if you have the frame too...