I don't really recall if it had the grooving in the crankshaft to push the oil back or not...or what the grooving looked like if it did.

They dont put rope seal grooves in newer stroker cranks do they?

I took my car onto the interstate (60 to 80 mph depending on traffic) for the first real distance.... Could of been a issue from day one, just now you your seeing it because it had full heat and thinned oil and good constant pressure.

Like the others say, pull that cover, id say anyway ya look at it, its a semi easy fix in the big picture.