My Street Demon install experience
See which you have either instructionwise, or if need be, remove the distributor cap and rotor.
If the shaft is raw steel and spring attaches to a heavy weight, its a Chrysler advance.
If the shaft is bronze color, and the spring attaches to thin sheet metal perch, its Mallory built.
Its a completely different advance mechanism
And RN12Y as pretty typical for 318/340/360 factory.
14 in my thinking is a hotter plug which I'd use if I saw fouling or if the FSM called for it.
If working alone, yes that's the easiest.
The instructions with the kit sortof get around the issues of different engine combos by advising to set timing at 2600 to 2800 rpm. Sometime later when MP had Mallory build the distributors, they changed it to something like 2500 rpm. (The Chrysler built version has a better advance.)
See which you have either instructionwise, or if need be, remove the distributor cap and rotor.
If the shaft is raw steel and spring attaches to a heavy weight, its a Chrysler advance.
If the shaft is bronze color, and the spring attaches to thin sheet metal perch, its Mallory built.
Its a completely different advance mechanism
Sure. I tend to think of RN9Y as basic 340 plug but sometimes too cold for street use and lower compression years/builds.
And RN12Y as pretty typical for 318/340/360 factory.
14 in my thinking is a hotter plug which I'd use if I saw fouling or if the FSM called for it.