318 LA rear main leak?
There usually is a gap on the sides so the the bearing face touches home before the sides so you get the right amount of crush on the rear main & it doesn't get hung up on the side face.
Usually i check with a plastigauge around .023
I use the Felpro BS 40245 or the double lip super seal from Mancini .
There is also the problem if any oil comes from the top valley plate or rear of the rocker covers the oil runs down the back of the engine & comes out the same place a leaking rear main does.
I doubt weather spinning the oil pump will help as most of the rear main leakage comes from when you take off & oil in the sump splashes on the rear main seal & when braking it splashes on the front seal
Also check you have a pipe hooked up to rocker cover via the PVC valve from the vacuum it helps to create a slight vacuum in the engine to help with leakage some guys put 1 to both rocker covers
My 318 LA is on the stand, its a tight gap.[/QUOT
Ok so I pulled the sump tonight & removed the rear main cap all looked ok
I removed the lower seal & fitted the main cap with tight bolts & same gap was apparent.
then I removed the top seal & rear cap bearing shell & refitted & same thing I have a gap.
then I checked the rear cap with a straight edge after removing again to find that it looks flat to me & it should sit flush on the block.
Here are some pics