I agree with flatfour on it Ceramic bearings per your engine application being a overkill, at $73 Bucks....WoW! The major differance between ceramic,as aposed to your polished harden steel bearing is that Ceramic will not generate heat comparitivly. Bearing wear starts and ends with Heat & Friction, Therefor requiring better bearing performance on a 40,000 rpm engine as with 20,000 range. Standard bearings "usualy" do not offer longivity in anything other than "slow moving", "light duty" applications. Bob, I gota go with door number #2...The high speed bearing. I've changed a few.....thousand bearings in my time. Good luck! Pre1960