Tell that to the Chrysler engineers who still recommend a full groove main bearing for a performance application to adequately oil the rods. Although I have noticed on modern clevite "H" series bearings that the oil groove is not nearly as wide as it was in years past.
To my knowledge at the time of assembly Mahle did not offer a full grooved main bearing set for the sbm.
But I noticed later that Mopar performance was selling "H" series bearings fully grooved with the narrow #5 main. They must have had them made by clevite. So Chrysler still believes in fully grooved mains.
