What size spark plug wrench for 5.9 dodge ram 1500 engine?

The 5.9L Dodge Ram 1500 engine (typically a Magnum engine) uses a 5/8" spark plug socket. You'll want a spark plug socket wrench, not just a wrench, that's 5/8" to properly grip and remove the plugs. Make sure it's a quality socket designed for spark plugs, as they are often fragile and need a good grip.