I have a buddy that has a whole spark plug collection and a majority of the early ones are nothing but gimmick on top of propaganda to sell the unique but not necessarily functional design. A number of them talk to plug fouling. I suspect that the design of the plugs I have are probably work real well on a low compression, constant RPM, stationary engine. They look cool on the engine but that is as far as they go. I suspect that they were getting hot enough that at higher RPM they were igniting like a diesel on compression. Now I know why the valve cover on my Cragar/Miller says 'use high compression plugs' The gap on the 'First American' spark plugs is at .040 and there is no way to adjust the gap smaller. I've gapped the Chumpions at .032 and they are working well. I've gained 2 to 3 MPH on my calibration hill. From a dead stop at the bottom I can now do 47 to 48 MPH at the steepest part. Up from 45 MPH.