For as really permanent fix, have the block and rear main cap bored to fit a Chicago Rawhide #38647 full circle lip seal. That requires stripping the engine down to a bare block and setting it up in a Bridgeport mill, or using a fixture like I designed a couple of years ago that adapts a cylinder boring machine to the back of the engine block. Setup on the Bridgeport takes several hours, and is very expensive. With my fixture in place, I can be making cast iron chips in 30-45 minutes, and the whole process takes a bit over one hour to complete.

https://www.zoro.com/skf-shaft-seal-3-78x4-34x38-crwa1-nbr-38647/i/G9397674/

Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!