Thanks Adam,

This is basically what I have started to do. I found a huge vacuum leak at the EGR and also at the thermo switch to the EGR. I've got that line that connects to those plugged for now. I've replaced most of the rubber connectors and vaccum lines as well as the vacuum switches and the bleed off valve. My modulator seems to hold vacuum just fine. I've even replaced the main brake booster vacuum line. I suspect my modulator may be faulty somehow, as I just backed it off one complete turn and it has only slightly improved the shift quality. I'm under the impression that the modulator is more sensitive than that?