I'm about to change Spark plugs which were originally H10's which I know they do not make anymore. The cross reference on these show H10C or RH10C which are both the same mm, reach and head size as the original.
I just want to be sure that these also carry the same heat range as the originals.I have a call into Champion Spark Plug Co. (Federal Mogul) but they have not been to quick to respond. Does anyone know if they are the same or what the difference may be if any. Thanks