66 273 Commando Clutch HELP

That’s the old Auburn style 9.5” pressure plate. You can “upgrade” to a 10” Borg & Beck style pressure plate (like the new one in your picture) and still use the 122 tooth flywheel. If you move to the 10.5” pressure plate, that requires a 130 tooth flywheel, different bellhousing and release fork........ a lot more parts for just 1/2” of clutch. I tossed the 9.5” Auburn style out of my 1967 Formula S and went to the 10” Borg & Beck. Everything lined up and it works perfect!!