I've got a pan sitting under the engine area of my '76 to catch the droplets of oil that fell before i changed the VC gaskets. No problem, no more oil. However, after moving the car back to its normal resting place, i noticed the next day that the pan was full of what appears to be water.

I am going to ask a stupid question, but did you wash anything down or the vehicle?  It ain't normal if you did not wash anything.  I would check to see if wiper resorvoir is leaking, etc.  Also check your antifreeze to see if there is any consistency between it and the water

Clarify what you mean by pan FULL of water. Lots or drips? General area under the motor. Front, back, drivers side? Could be heater hoses, or I've seen a few motors with water passage leaks at the intake manifold gaskets. I had a slight drip that looked to be coming from the starter area and from the drip hole in the flywheel cover and that's where it originated from. 

I also had a heater hose connection at the front of the motor that let water flow along the valve cover and drip down at the same spot as before. I thought oh no, intake gaskets again!! At least that was an easy fix.  That started shortly after I replaced the intake gaskets as the hose clamp must have dug into a soft spot in the hose.   Mike

mkapp78792007-01-29 17:11:02

A little more info, maybe?
Is the liquid you see clear, or green, like antifreeze? That would help determine what it actually is. If you did any cleaning after fixing the vc gaskets, it could just be residual from that. Plus, if there wasn't any of it before you changed the gaskets...
Then again, you may have moved a hose enough while taking the vcs off/on enough to start a leak at one of the hoses, like the heater hose Mike referred to.