looking for detail info and pics on raising bed floor

[hellbent72]

I am needing to raise my bed floor 12inches to clear rear back halfed frame rails. I'm not really findind much as good detailed builds on it. I have found a few pics but not a whole lot in depth.
My questions are.
Are most raising the cross braces up with the floor and building perches off that to connect to original frame mounts ? or are you keeping the cross braces in place and raising the bed floor sheet metal and building a new frame to set the bed floor on?
Any info would be great so I don't find out a better way after I get in to deep. Thank you for any help