That's a fuel issue. It's running too rich (too much fuel). How does it idle? It could have a blown power valve. That carburetor is a nice one. I have one just like it on my dining room table. It has replaceable air bleeds. You can tailor that thing pretty much however you want to. It's a carburetor issue. Not an engine issue. You're fixin to spend a pile of money for nuthin.
I had rebuilt it prior to parking it, so i thought maybe i just didnt have a good seal on an intake valve. out side of the power valve what else could be suspect in the carb? Idles kinda choppy but smooths out at higher rpm