In my 84 GB I replaced my old Grunert unit with two separate Frig-a-boat systems. It was a DIY project and not so difficult. I kept my two boxes and removed old plates a compressor/condenser. I put my new 12 v refrigerator compressor/condenser (size of a loaf of bread) in my engine room and the freezer compressor/condenser in the salon under a seat nearby the freezer. What makes it an easy install is the evaporators and tubing come pre-charged and all you have to do is connect and tighten fittings to charge the system. No charging equipment, gauges, etc., needed.