The best fix is also the most difficult- - - -machine the back of the block and the main bearing cap for a full circle lip seal like the one used on the late model Chevy small block V8. National, SKF, and several other brands of seal have a part number that fits. The dimensions are 3.875 shaft diameter, 4.750 outside diameter, and 0.375 seal width. There's also a "speedy sleeve" available that puts a smooth stainless steel surface on the crankshaft hub. The downside is that the engine must be torn down to a bare block before doing any machining.
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!