My Dads '50 with the 6 ran perfect it's whole life. Completely stock until he put a split manifold on it. Never an issue, started perfect, ran perfect until a piston top detached from the skirts...after 60 years. We figured it was because he would pull 2 trailers to Cushman events. After a while, it was just too much.
Stumbles on acceleration usually lead to a few things, accelerator pump, timing or vacuum leak.