hesitation

A coil going bad can do this. Coils are cheap enough it might be a good idea to just replace it. Just make sure you get the right one. 

I know the most sudden carb changes are from a heavy float...this can literally happen in no time.  Of course this over richens mixture and can cause a fire at worst.  The thing is, it seems like a lean problem.  Have you tried taking the pre-pump fileter out and blowing thru it with mouth to see if its resisting flow?  My gremmy would still have silt in it from its sitting for 13 years , and the tank had been cleaned (badly) and sealed.   

Edited by Thikstik - Jul/04/2018 at 4:39pm

Before you rebuild the carburetor make sure the spark at the spark plug is blue...not yellow...if its weak...Id look at the condenser.....

This might be a long shot, but have you checked the connection of the coil's +/- terminals? If they're spade connectors, you might be running into a similar issue as I was with my Eagle shortly after I first got it. Abrupt jerks, stops, and even movement from firm shifts could cause everything from that hesitation you described to outright stalling and no-start conditions as time wore on.

It drove me absolutely crazy, because air/spark/fuel checks would all pass, as something would be jostled or repositioned while I would be poking around, which would get the connector reseated. I even pulled the connectors from the cap, brushed them down, and cleaned them to make sure they were getting a good connection!

Turned out that the negative connector retainer in the cap had worn out just enough to let the connector back off under certain conditions. It took having my buddy move the wires around while he was checking spark as I tried cranking it before we finally confirmed that I was losing spark intermittently. From there, I tossed the cap and pinched the female spade connector over the coil terminal, then wrapped it tight with silicone tape so that it wouldn't move until I said so (which was when I pulled out the duraspark ignition for an HEI setup a couple days later- not as a troubleshooting or repair step, just what I wanted at the time. Eagle drove fine after the terminal fix).

If you have threaded coil terminals and ring connectors, then it's probably not the same issue . Still might be worth making sure that you've got a good ground to the block via the coil retaining clamp. Things got wonky with my Gremlin from the clamp getting loose, in combination with the bolt threads and hole getting packed up with crud over the years.