273 Engine Help

I was having trouble with my car hesitating and being "gutless" on acceleration. I got checking around, and found that the vacuum advance unit on my distributor wasn't working. I ordered a new one from Autozone for about $20, and it should come in tomorrow; so I'll post back and see if it fixed my problem or not.
I did the "red-neck" check: pulled the vacuum line from the carb, pulled the cap, and then sucked that line to see if I could advance the dizzy. It was like breathing in through a straw! I though that my vacuum line was bad, so I pulled it, plugged an end and tried to breathe - that line is solid. The vac advance unit is held on by two screws, is easy to get out, and replacing it should be a snap.