Hud1,
Just a couple toughts:
Too much oil pressure at the begining, worn out cam bearing due to excessive effort to turn the oil pump shaft, check out the distributtor for excessive wear between shaft and housing, a bent camshaft etc...I believe a bent cam or a heavier than required oil weight making too hard to turn pump the culprits. The Cam walking back in the gear and the 2 bearings dead may go to the too much effort to turn the pump route.
