Yes zero lash plus a turn with hydraulics on a mechanical cam designed to have clearance ramps will throw a whole bunch of unburned fuel in places it shouldn't be. Now you must pull your push rods and make sure they are not all bent. Lucky rock auto has them dirt cheap if need be. I'm betting they are bent, at least on the intake sides.

Last edited by sstock; 10/06/2019 4:35 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