First off, hit the basics. Do you have fuel flowing? Do you have spark?

You found a NEW, not reman carb for the /6? Didn't think they still made them. I have found, from past experience with /6 carbs, that at least the reman ones are junk. I had an issue with my 225 getting like 8 mpg, turned out the reman carb was jetted way rich. Fortunately, it was a Holley and I was able to buy the correct et for it.

I also helped a guy troubleshoot his /6, wouldn't start. Turned out the carbon core of his coil wire had eroded back, inside the insulation, so far that it would no longer jump the gap and fire the plug, about 1" was missing.

The best way to set points on a /6 is to pull the distributor and set it up on the bench and while you are there make sure the drive gear is there, the guy above had a plastic gear that he fractured trying to "adjust" the "points" on his 77 Ram (he had electronic ignition).

Couple of things to look at.

Also, your original problem sounds like a vacuum leak. If you want help on setting up the carb, tell us what year, make and model too.