12 Volt Conversion

[Mustanggsrule]

Hi, I'm new to the forum, I have a 1952 M37 which has been converted to civilian 12V ignition for a fire fighting truck. My question is about spark plugs, I have Champion J11C plugs in it, but when you look online there are always numbers that follow that J11C designation, can anyone tell me what those numbers should be ? Or is J11C the only numbers I need, thanks. BTW I am upgrading the distributor to a pertronix kit with a new 40,000 volt coil. Thanks for your help

[Cal_Gary]

Welcome aboard and congrats for saving another one! I'm not aware of any secondary numbers necessary for the plugs unless it's for the heat range-mine is also 12V and I run civvy plugs and wires. Just install a new set and gap them correctly. There are many vendors helping us keep them operational-several are forum members and freely offer their advice.
Gary

[jimmy_stikx]

I just took one in with me to Autozone and had them cross reference it to 6 that would work for me.

[Kaegi]

its a good time switch to autolites. champions cant take the heat. centers melt right out of them.