If you want to brush your engine paint on I have used the Por-15 engine enamel (Buick Green 53-65) and plan on using it again. Sorry not sure if this would be correct for your Riv. www.por15store.com The semi-gloss black is my preference for the engine compartment items. While that engine is out please drop the oil pan and clean it out and check oil screen pick up too. Dynaflow correct color, not a clue. Bill Hirsh (paints) out of Newark, NJ also has paints for our Buicks. Listed in Hemmings. Enjoy! Doug.