I was able to get the prefilter sealed, I even tested it with a Mity-Vac and had no leaks. It would still suck bubbles down into the SOV. I tried replacing the prefilter, with an old style prefilter.

The problem with air in the line from the prefilter to the SOV is that the lift pump will suck air from the upper end of the prefilter down the tube. This occurs in both the instance of the "stock" prefilter and the "modded" prefilter. Looks like I will be taking the IM off once again (third time this year) to test each component for vacuum leaks.

I like this car when it runs right.... which at this point is about 3 months out of the year. Sheesh, I should have bought a MG if I wanted to work on the car this much.