You're in luck- - - - -that's the later style bearing. The early ones had dowels on top and bottom, and used shims to adjust the clearance. The tabs on the upper bearings started in mid-year 55, IMHO, and went to 62/63. The early blocks can be modified to accept the later bearings, but then the crankshaft has to be custom ground and polished to get the right oil clearance.
Jerry
Outstanding!! Thanks for the info.
FWIW, this engine had no shims at all on rods or mains.
