Really bogging down in 3rd gear

Hmmm, my last post did not take..... Tyler's descriptoin seems to me to be a pretty fair distinction between weak ignition and weak fuel.

The points distributors through 1969 should work. Not sure if the advance curves changed much, but I suspect just about any one would work for your car.

I will agree that the points cam on the distributor is not a common issues. But wiht fewer drivers knowing how to take care of them, then this wil be a more common problem. If the OP observes that the points on the distributor cam are worn unevenly, then it has become an issue. It will be difficult if not impossible to have uneven wear and not have the points operation erratically from cylinder to cylinder. Not only will the dwell vary but the actual spark timing cylinder to cylinder will vary.

He should compare the cam points carefully and if they are really erraticly worn, then it is time to replace that part. It may not be the cause of this present set of issues, but it needs to be corrected. If they are not highly worn or not worn unevenly, then move on to another of the causes mentioned. Vacuum leak (since the carb has been worked on in the last few months), and fuel (since that is such a common issue with old tanks).