fasbak
Well-Known Member
O.e. Heat range[cold] for '68-'72 340 motors by champion[ o.e. Mopar spark plug manufacturer for factory engines]. I have [8] #n9y[exact plug in '68], [36] #n9yc[ with copper core], and [8] #rn9yc[resistor w/ copper core] available. Factory engineers have long stated that the 340 performed best with a cold range spark plug. They were later replaced with n12yc [hotter] spark plugs which suited many of the lower compression engines of the early to mid 70's v-8's and beyond.must buy in quantities of [4] or [8]. $3.50/plug shipped anywhere in continental u.s.***shipping only to continental u.s.***
