Well, I went out and worked on the car last night for a bit.

When I got under the hood and started working on it, the first thing I noticed was the timing was WAY off. It was set about 4 degrees retarded. So I placed a vacuum gauge on the ported side of the carb and it indicated it was pulling 5" vacuum (I assume this means that my carb was not in the idle circuit when at idle, but it was actually in the primaries).

So, I went about retiming the engine. I disconnected the vacuum to the distributor and set it at about 11 degrees advanced. I then lowered the idle which brought the ported vacuum reading back to esentially 0 (maybe it was .2). Then I dialed my timing light for 36 degrees, and ran the engine up to about 2000rpm and watched the mark come back to 0 on the crank. Finally, I hooked up the vacuum advance, set the timing light for 48 total degrees timing, and reved the engine back to 2000-2500 rpm. Again, the crank reading came right back to 0 degrees.

At 1500-2500rpm my carb ported vacuum port is pulling 15-20".

I didn't get a chance to drive it last night after the changes. I can't believe I was almost 15-16 degrees off in my timing. I guess the distributor wasn't tightened down properly. I'll try to drive it around tonight or tomorrow to see if the MPG goes up.