1975 F100 frame up build. Full interior cab cage built into the sheet metal for extra strength. Note seat frame mounts tied into door bars. Brackets welded to the tubing bolt to original seat mount holes in the floor pan.
Joining cage tubes to interior sheet metal makes the cab much stronger for off-road use. All cage work goes through the cab floor to the frame using Autofab bushing assemblies. This creates extra body mounts and allows the removal of the cab from the frame.
Rear frame section before shock mounting and cage structure. Note bushing assembly mounts at the front spring hanger, middle of the frame over the bump stop, and the very back behind the shackle mount.