Depending on how/if the engine was rebuilt, there's ALOT of reasons that could happen.
Blocked return holes.
Partially restricted pushrod tubes.
Improper oil pump timing.
Improper head venting.
Excessive blow-by due to worn rings.
“When the going gets weird, the weird turn professional....” ~ Hunter S. Thompson~
R.I.P. Rubberdown. 1971-2012
2005 E.G. Classic
Baisley Oil spring
Rinehart 3.5" pipes
S&S adj pushrods
3 stickers, adding 5 hp each. I swear......