I agree on the dwell meter, I have replaced my points so many times I can get it pretty close with just a screwdriver and my wits, but the meter will give you an exact number to go from. You can even gap points that are basically bad (pitted, etc) so that they well run ok, something that you can't do with a feeler gauge.
NAPA is my first choice for ignition parts anymore. The store here has people who have a clue working there. Last time I went to Shucks the guy didn't know what points were, as in no clue at all. I asked for muffler bearing to go with them and had him looking that up in the computer as I walked out laughing my head off.
Could be you should look to upgrade to electronic ignition instead of just getting another points disti at the junkyard. I'm sure it couldn't hurt your problems.
