On another thread a member said that some VW guys were using a needle valve with a glass ball in order to run higher fuel pressure in the 48 IDA. I Googled that and came up with a site that sells them, with this explanation:
These Needle Valves Are Special Made With A Lightweight Glass Ball, Eliminating Flooding Caused By The Overweight Steel Ball That Our Competitors Sell. The Glass Is Less Than 1/4 Of The Weight Of The Steel Ball Which Allows You To Raise The Fuel Pressure. We Have Run Up To 9 Pounds In Our Own Cars.
If the problem with the original seats was that they leak under higher than recommended pressure, how would a lighter ball help that?