Make sure the rotor is seated on the top of the distributor, then recheck the point gap like Martin says.
Carl is right usually the carb gets the blame, you didn't use teflon tape on the fittings did you on the fuel line?

Last edited by sstock; 10/06/2019 1:24 PM.
1953 Chevrolet 3100
261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done
In the DITY Gallery
Video of the 261 running

1964 GMC 1000
305 Big Block V6, sm420, the next cab off restoration