Fell on my face tonight

[chrismoore701]

Well here is the history and story
1979 c10 frame off. New painless harness. Finished the build last year. 3,000 miles since build
Took her out sat and smelled something odd. Couldn't find anything. Later that night noticed voltage gauge reading under 12. Pulled battery cable and died. Confirmed alternator.
Bought an autozone special for $45 because that's all they had. Put about 50 miles on today and noticed she started to sputter. Kind of like plugged fuel filter. Then it got worse. She fell completely on her face. Had to limp home. Almost like a miss. No power shacking terribly. Then bam. Full power. Than on her face again

Any thoughts? Could the alternator have anything to do with this? Seems like a multiple miss. Like 2 or more cylinders. Was going to pull the plugs and check but anniversary tomorrow so I came to you guys to get some ideas before I tear into the issue

Thanks