A stock hydraulic cam in these 110 hp marvels is so mild, probably the cheapest oil is fine. It is too bad they changed the old Quaker State Defy. Available almost anywhere, 1000 to 1100 ppm ZDDP, on the higher end of the allowed viscosity for a 5 or 10W30 weight. Now they still claim more zinc but an SN 30W oil is only allowed 800/900 ppm ZDDP. There is info on the PPM on nearly every brand. I just picked up some old stock SL and SM 10W40 in the Sonic(Coop) brand, I am a fuel truck driver for them. I actually had issues running Coop's high ZDDP diesel oil in my Olds V8's. I don't know if the detergent or other additives caused the piston rings to stick but they did. We use the good, shipped from the US to our refinery in Regina, POA synthetic base for our oils. Our company even had a SN rated 20W50 synthetic blend they will be discontinuing. I put 5W50 full synthetic, SM rated, Motorbike oil, supposedly has a hyper ZDDP package safer for catalytic converters in the Olds 350 for winter use.