The stumble is probably lean, and/or late timing. A degree or two of dwell change isn't likely to make much difference, but if you'll time it a ball's width or two before the timing pointer you'll see a much better off-idle response. Adjust the idle mixture to the best manifold vacuum (not distributor vacuum) plus 1/8 turn rich and set the idle speed to 450-500 RPM after adjusting the mixture.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
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