As I said, it's a very simple procedure to adapt the later model bearings to the early block. The bore diameter in the block is the same, and all that's needed to run the newer design bearing is to grind a divot at the parting line to accommodate the tab on the upper bearing. The lower bearing still has the locating dowel with a corresponding hole in the cap. Oil clearance can be adjusted with shims on the older engines with either design of bearing.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!