Minor plug wire arc

[challenger57]

Is in total darkness a very small arc at the plug end of the plug wire acceptable? I have accell wires on my 360. I have been trying to get a steady timing on this thing. When I installed a new cam and even prior to this it did not have a steady timing. I put the mancini timing chain tensioner on at time of install with new chain and sprockets. It would vary about 2-3 degrees. Then I saw in fabo the bushing on the distributor shaft trick to hold down the oil pump gear. This brought it down to about 1 degree variance. Could it just be the old oil shaft is worn even though it is being held down or could the plug wires still have a factor. And also what is the best air gap for the dist. My old shop manual says .008 and this is a stock dist. but am using a MSD 6al box.

 

[krazykuda]

No, if you see a spark arcing, then it's not getting to the plug, replace the offending wire...

Watch #5 & #7 as they are prone to hit the headers and exhaust if not properly kept from hitting them...

 

[67Dart273]

It might NOT be the wire you are seeing arc. Can be crossfire, etc

Check all plug wires for continuity. Pull them off one at a time, hook up the meter, and shake them around, looking for change on the meter. This, actually, is best done with either an old analog meter, or at least a modern digi meter with a bar graph to simulate analog

Examine plugs for cracks. If there's any doubt, replace the plug.

If you can't find anything, examine the offending wire for cracks and damage.

The jumping timing could be an indication of an open, IE open wire or cracked / bad plug. Don't discount that you might have lost a ground electrode on a plug!!!

And of course make certain the firing order is correct