What are the best spark plugs to use on 1978 Chrysler 400 engine?
- Thread starter Fred A
- Start date
RemCharger
Active Member
NGK XR5
NGK XR5 V-POWER
Tons of variables here. any Mods? I would read the plugs in there now and go from there hotter or cooler.
Last edited:
commando1
Old Man with a Hat
Exactly what the manual calls for.
Any of these fancy whoop-di-doo plugs will not give you even 1 hp more on a 45 yo engine.
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