I don't have a good pic of the problem.
But, I am telling you this is the problem. I talked to some real experts on this. It's about components. It's about math. You have to measure everything. Something is out of tolerances. Things don't fix a leak because of knurling or smooth polish on the crank surface, grooves in bearings, or the grinding of OEM retainers.Ropes seal don't last and 1960 and 70s era motors did not have rope seals. It's about tolerances.

when we found the measurable problem. We did not even have to test the solution on the stand. We knew we had solved the problem.



Here is one guys solution that started our research I found on another site. He was very helpful. Our solution was similar but using micrometers. His discussion saved my engine (he was a saint!):


Install The rear main lip seal half in the block "flush" with the cap parting line.
Install the Crank.
If your Lip Seal compression on one side, is less than the other under close inspection with a light, with the Crank in the block, you have a potential for a leaky main.
Gently, using a small screwdriver, GENTLY, insert it behind the offending side of poor compression, and "eyeball" the amount required to equal Lip compression "side to side".
DO NOT damage the back of the seal with the screwdriver. It doesn't take much.
Record the amount required to move the lip seal into equal compression.

Now dis-assemble.

Re-assemble this time, with the Block side Rear Seal lip half protruding approx. 1/4" above the parting line on the offending side.
Reverse the same Seal offset installation in the Retainer.
Now use the Retainer when installing, to CAPTURE and DRAG the offending poor contact side over into proper seal lip compression, the same amount as you recorded earlier, as you Tighten & Torque the Seal Retianer into place.
Silicon up the sides of the Seal Retainer to the Block, deleting the paper inserts. (The paper side inserts probably won't go in anyways due to the Retainer offset installation)