Surprisingly, most of those parts do not interchange. here's my recap from this past year when I had both an '82 GL and an '80 CX Deluxe. It will also depend on which CX you pick up, Deluxe, early Custom, late custom, etc.I am considering parting this GL500 out, or picking up a rough CX and having this for backup parts (because ordering parts from ebay get VERY expensive.)
I believe the intake manifolds are different
Carbs are %100 the same?
Does a CX chrome fender fit on a GL?
suspension is different
handlebar switches are different
front rim is the same
rear is 16'' on GL
different ignitions, tdi on GL vs cdi on CX
air box is the same?
exhaust and H box is the same
Intake manifolds - nope, different carb spacing means different intake manifolds.
Carbs - Sort of. the spacing between the two is different, but you could use GL carbs on a CX if you use the CX racks, transfer tubes, etc. I mixed and matched a CX left carb with a GL right carbs to solve a damaged carb body.
Front Fender - Nope, if memory serves. The mounting points are different. I tried to use a spare GL fender on a CX and couldn't.
Exhaust system - Sort of. The headers can be swapped, but the hbox, heat shields, and mufflers cannot.
Airbox - Nope, different.