Bucking Mustang

[kechke1]

My 331 , AOD, with Holley 670 bucks and shakes violently when I shut it down in neutral. Idle rpm in gear is 700, 900 in neutral. Does not kick back in gear shut down.
Crane optical dizz with Crane Hi 6 ignition box.
14 initial and 38 total timing.
Any suggest on how to stop this?

 

[7991LXnSHO]

Does it run smoothly when it is on?
Does this sound right?

Curing running on

Running-on is when the engine continues to turn after you've switched off the ignition because the fuel /air mixture is being ignited by a hot-spot in the combustion chamber . Furthermore, because the mixture is often firing at the wrong point in the cycle , the engine does not run...

www.howacarworks.com

 

[kechke1]

Any rpm above 1K runs like a top. It does not run on, just thrashes around before it finally quits.

 

[7991LXnSHO]

Brainstorming - vacuum leaks, ignition problem, carb idle screws and floats not set right, Holley power valve not a 6.5” or blown out, evil possession…?

 

[kechke1]

Thanks.
Tomorrow I’ll put a vacuum gauge on it and investigate further