I've solved the majority of my restoration issues (clutch, air cleaner clearance, etc) but discovered a new one today.  My 5 year old boy recently discovered Corvettes have pop-up headlights.  When I told him ours does too he became pretty excited and kept asking me to try them out so he could see them in action.  Imagine his disappointment when we started it up and the lights would come on but not pop up.  I didn't have any time to troubleshoot today but any thoughts on where to start?  I DID hook up the main line to the back of the manifold, but, now that I think about it, I didn't pay any attention to the orientation of the short piece of hose that has what I think is a one way valve?  If I got that in backwards I'm guessing I'd get no action?  The other thing I thought about is the two hoses that connect to the headlight switch - does it matter which way they're hooked up?  Since the whole dash was off they've definitely been messed with since the last time this thing ran...

Dave..."You've got MAIL!!" 
I sent ya Gilbert's excellent color coded diagram, along with some other stuff that should get ya flipping up/down in no time.

Send that too me also Adam!!  I can put it with the rest of the "Corvette fix-up" stuff I got!!

Just went thru this on my car and Joel sent me a great color coded diagram. I also followed the vacuum 101 troubleshooting guide that was posted and I had more than 1 bad part. I also ended up replacing a brand new headlight switch because the first one was defective. And yes it did make a difference if the hoses on the switch are backwards. Follow that diagram that Joel sent you and it will come to life for your son! Best of luck.
Rodney

Just so everyone knows, Gilbert sent me the color coded diagram. He did that hisself, and was kind enough to share with us. I'm just passing it along.
Dan..."You've got MAIL!!"....

Joel, thanks for sending and Gilbert thanks for the original post on this color coded diagram.  Very helpful.  I should be able to pinpoint the problem now.  As for the suggestion to "start at the front" I think I'll start at the other end since the only things I messed with are the headlight switch, manual override, and manifold source vacuum.  Hopefully it's one of those three, all those hoses in the front are too scary for me.  

The filter is a small, round plastic piece, usually white(or tan, with age), with only one nipple on either end, and it does not really matter which way if fits into the vac. line.
The one-way valve is metal, usually silver, with one nipple on the intake end, and two nipples on the other side. The valve goes with the single nipple end connected to the filter, and the dual nipples going out to the car.

Just to close the loop on this one - the two hoses on the headlight switch were reversed.  Pretty easy to troubleshoot: override switch would pop up the lights, but when I turned on the main switch with the engine running I could hear some sucking going on behind the dash.  Had the fun of taking all those pieces off around the windshield so I could pull the dash pad back enough to get to those two hoses.  Started 'er up after that and we had pop up!  Had to take it back out after all that to test.  (and to go through the local drive in).

Could you send me one too...