Posted By: flatiron
spark plug cross reference - 07/13/10 01:41 PM
Trying to cross reference plugs and it's not going well. I am currently running a champion RN11YC4 and we feel it's to hot of a plug and I'm looking at Autolite's 403 or a AR-51. Are these 5/8 plugs and were are they as far as heat range goes when compared to what I'm running?
