Take a look at the condition of the bearing nut/oil slinger and the inside surface of the bearing retainer where the two match up. If one or both are worn excessively it could cause the problem you are having. The gap between the two components is about all that keeps the oil from working it's way out the front.
Fred



1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine