The only thing common to this problem is the block- you have changed crank-pistons-rods etc ,but all still in the same block and the same bearing ( # 3 if I read your posts correctly ) which feeds from the center main bearing. Now you mention that prior to the bearing problem occuring that the car was involved in a minor accident--- could this have hit the crank on the snout & damaged/cracked the center main web to create an internal
oil leak and reduce supply to that bearing, remember this is the thrust bearing, any hits etc are felt here---- or is there a end float or spigot brg problem that is causing similar issues. The center ( or Any ) cam bearing can also cause a localised loss of pressure at each main journal if it has delaminated and lost some bearing metal.