Hi folks, I can't find non-resistor plugs for my 57 392, are resistor type ok? R45XLS (AC brand) vs the 45XLS that were in there. Also, the manual says don't use the gaskets on the plugs, I never would have guessed, glad I read it. I bought new rubber doughnuts for the tops of the tubes, the old ones were hard as rock and cracked in places. Any other comments/tips appreciated. John