One thing to remember when you're on Summit.com buying $30 a quart gold plated oil... tens of thousands of Japanese people drove these motors around that tiny island. Most of them were probably serviced by the Nissan dealership or a Jiffy-Lube equivalent (Jiffy-san?). They almost certainly got 10w30 dinosaur juice.

Just put some oil in the crankcase, make sure it stays there, and change it every 3-5k miles just like you would any other motor. There is no reason people running sidemounts on 7psi need anything more than Penzoil.

BTW, heavy stuff like 20W-50 has been known to cause oil pump failures because it is so heavy. Something to consider.