OK ... all systems are go again ... at least I hope so! I drove up to the far-away dealership to get my parts, and they had everything in stock ... and a REALLY nice parts dept., worth the drive. I replaced the switchover valve and both lines as well as all the rubber connectors. I cleaned the nipple on the intake and gently cleaned the tip of the nipple on the ALDA (it was pretty clear already) and also cleaned the contacts on the electrical fitting before I put it on the new switchover valve. I took it for a drive and everything seems fine ... the car feels a little livelier off the line, which would make sense, given the incredible amount of crud in the lines I took out. It also might just feel fast because I spent the morning driving my mom's big dog of a Suburban!
A couple wrap up questions:
1) What exactly does the electrical switch on the bottom of the switchover valve do?
2) What is the other line that comes out of the Y fitting on the ALDA? I did not change this line, just put it right back into the new fitting, and tried to be as careful as possible with it. It seems less brittle than the other two, and it was clean, so I figured it was OK. What does it do?
3) How do I know I did this job right? It looks good and drives well, but I don't want to pat myself on the back just yet ... close, though ... I actually got something done!

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