I have 1989 3.0 mercruiser the spark plug part number on the motor is AC MR 43T is this ac Delco plug can I get this at an auto part store? Or another plug part number I can use.
Should be able to get them at Napa Auto parts. If they don't stock them they can get them in a day or so. Napa has a whole marine catalog. Not sure about the local autp parts stores.
M= Marine (corrosion resistant)
R= Resistor plug
4= 14 mm Thread size
3= Heat range of plug (lower number is colder plug and higher number is hotter plug)
T= Tapered seat
I got new ones for my boat a few weeks ago at NAPA for $2.07 each. May sure you gap them to the correct specs as mine came gapped at 0.040" needed to be 0.035" for my engine.