zzrodder
It ain't grey hair, it's chrome!
I think the best argument for making the bed a bolt on is the frame design. There is bound to be some flexing going on since that frame was meant to be bolted to the Caddy lump of a body - if you weld the much less rigid box to it, there's a good chance for cracks to show up. Bolt on mounts should give it a some ability to move around a bit and hopefully give it a less stress free life....