I know you said you rechecked your valve adjustment but popping through the carb is a sign of too tight valve adjustment. Are you double sure you dont have mechanical lifters and you are setting them like hydraulics? Truck engines have mechanical lifters and cams, or did you put hydraulic lifters on a mechanical cam??

Last edited by sstock; 10/06/2019 12:58 AM.
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