It has been my experience that higher Rpm's within reason are a lot better
for an engine that lugging it down. We rebuild a lot of motors that have
had too big of a prop with ceased rings. Engines run at higher Rpm's stay
cleaner. You can run your engine at 7,000 - 8,000 Rpm's safely.

The 500 Rpm difference you mention is if no significance.

Don Dando