Which is the best spark plugs???
Auto-lite…they are the o.e.m. recommended plug…and as a rule for domestic vehicles I have always had best results by following the specified plug for each make of car…auto-lite for mopar products…motorcraft for ford…and A.C. plugs for general motors…and it seems all auto-zone and advance auto want to promote is bosch…and as they may be a good plug in somes opinion…I have only installed them at customers request or in emergency…many times they come new in the box not working as good as the old ones I pulled out…and if you are still on a points ignition be sure and gap them all at .035…and for the best performance if you are gonna change plugs do yourself a favor and make it a complete tune…inspect or replace plug wires…points…rotor button and distributor cap…nice car by the way…I have always wanted a 1973 Dodge Charger and restore it myself and paint it black…if you ever hear of one in a reasonable price range let me know !
It is not until the engine is modified, or the compression is raised significantly, that stock ignition systems and spark plugs begin to show signs of being inadequate. I would choose an OEM spark plug that is for your vehicle. Iridium is the best all around but it is very expensive. Platinum is good for engines that do not use forced induction but it can stand more heat longer. Copper resistor plugs are used in a lot of cars and should not be replaced by other types because the spark ignition can malfunction with other electrical components in your vehicle. Like I said before, use the stock OEM equipment. The manufacturers spend millions of dollars developing tests for your vehicle so you can have a reliable means of transportation. I’d get autolite resistors.
