I looked at the 409 stuff too as i have screw in studs and have decided to go to 7/16, it gives me lots of choices for rocker arms. Its a big difference up here for price and also i have a better chance at getting a partial set of bbc rocker arms.
I am also contemplating making a oil deflector that will mount on the inside of the tall valvecover to keep oil down on the rockers i really think that is also part of the problem time to do a lift check on the cam thats in this thing.