The nightmare of a "spun" rod bearing keeps many folks awake --they Fear it in some crazy way that just does not line up with the fact that very very few folks ever experience that problem--some racers go an entire career without ever hurting an engine--
Irrational fear of a problem that is very rare --
I'm not sure that's a Irrational Fear. IMO, that's the Most common failure, a Spun rod bearing. They spin from lack of crush/clearance or oil. My vote, Full groove for full oiling of the rod bearings. Not a Guarantee, but just extra insurance. 3/4 would be my next pick.
