Rear main oil leak

[cjw916]

I have read other threads on here but I would like some clarification. . .

I built my 440 25 years ago when I was 15. It was all done professionally and has run strong for many years. The car was rarely used for ten years while I was in college & starting life. Now I have the car again & it gets yearly 'project' updates & improvements. I slowly buy parts & tinker with my baby again.

Mechanically, she is almost where I want her. Big Wilwood brakes, 17" rims, Hotchkis suspension, a few more mechanicals (subframe connectors, p/s box) & I will start saving to rebuild the engine w/ aluminum heads & rebuild the 4-speed. Then I will re-spray her as $ permits (Az body), not that concerned w/ it looking like a 'target', I kinda prefer that she's beautiful to the trained eye, on the inside. :-)

When I put a new 6qt oil pan on her, when I did the suspension, I replaced the rear main seal w/ the standard seal, trying to stop an oil leak. It was not successful. The car loses about 1/2qt in 1,000 miles. It does leave a drip spot of 10-15 drops, overnight.

Remove the flywheel cover & the front of the flywheel is covered w/ flung oil, so I assume its the main seal. Is there anything else under the bell-housing that could be an oil leak?

What should I try next, the oversize seal from Mancini? Other suggestions?

How does ring blow-by cause main seal leak, I have a breather on one valve cover, PCV on the other. Can I improve crankcase pressure in any way, as a for-now BandAid?

Thanks for your guys insight.

Christopher Wagner