Radiator drain plug

[Metal396]

no actually, i think its the vacuum advance is getting WAY too much vaccuum, over advancing on rev's. Causeing the spark to go off when the intake valve is opening. Im going to hook up the vactory vacuum delayers, to slow down that advancment.

After i set the timing (it was WAY too far advanced before) it wasnt backfiring NEARLY as much at all, no flames, just a barking or coughing noise (opposed to the previous 2 foot high fireball with a loud bang).

How many vacuum ports are on the holley? thers one on the passenger side metering block that i have plugged off, theres one under the front fuel bowl wich im using, and theres one in the back, pointing to the passenger side for the crank case ventalation that i have hooked up properly. Are there any others that i havent seen? Thanks