If you do some reading, particularly over at the FE forum, I think you will find that people running Ersons with E-Brock heads and .090 restrictors have had a lot of problems flooding the valve covers with
oil and, as a result, excessive
oil consumption as the
oil will cover up the valve stems. Apparently, the Ersons put out a lot more oil than others and the stock drain back holes in the E-Brock heads arent big enough to allow the extra oil to drain back fast enough, causing oil to pool up on top of the head. It seems the consensus is to use .060 restrictors (some went as small as .040) with Ersons and E-Brock heads.