340 Chugging instead of Reving

Ok...back in the garage for the rest if the evening. So Far...
New NGK plugs - No change in cutting out. But it started quicker and idles better. Adjusted the timing and couldn't stop the stumble.
Next swapped out the coil. Same results as above.
Now im about to remove the distributor and trying the lock out suggestion. If this doesn't stop the issue, I am shipping the ignition out for test and repair tomorrow (Monday) morning.