Spark plugs for 31

Posted by Tom Baldoni on December 09, 1996 at 11:00:40

I am going to be replacing the spark plugs on my 31 pick-up.On the existing plugs, the two center ones don't have the metal ring between the block & the plug. The two outside ones do. I put rings on the center plugs & it ran real rough. Is it just a matter of re-gaping the points, or is this a sign of something else in the cylinder?Thanks, Tom