AC in AC Delco Spark Plugs stands ALBERT CHAMPION. Alberta Champion lost control of the Champion Spark Co in 1908 and then started AC Spark Plug Co. Ac was bought out by General Motors in 1909. Reference Wikipedia --Flint East
Champion RER8YC
Champion
Champion RJ18YC6
The laser 40500 Champion cross reference is for spark plugs. There are many cross reference data bases to show which spark plugs can be interchangeable.
The Champion spark plug rj19lmc should be able to replace j19lm. Many of Champions spark plugs are interchangeable with plugs with the same letter coding.
16 spark plugs total Use what the factory has in it. Champion re14mcc4 .045 gap
a gap of 0.7 to 0.8 for champion spark plugs
Champion
Champion
ngk BPMR7A
NGK BPM6A