[Singleton]

I believe that the 6485988 (RM) is the same as the 6486116 (RO), except the RO has the hole for the carburetor vent, (California carb). Both are non Ram Air dual snorkel. My understanding is the vent hole had a plastic plug in place on the RO when used on a non-CA car in 1970.
Seems the assembly manual is saying the Norwood used RA while Van nuys used RO, and with a plug if car was shipped outside Cali. I’m unsure.