There are three on each side and two on the rear.
MY 2000 dodge ram 5.9 has 1-inch and five eigths and 1 that is an inch and 1 that is an inch and seven eights. these are the three in the back of the engine .
1-1/2"
sasg
Probably 1 5/8".
Should be 1 5/8".
If you mean the freeze plugs......they are located on the bottom side of your engine. They are round and are about the size of a half dollar.
Freeze plugs are located in numerous places on the engine block and cylinder head assemblies. Replacement of freeze plugs is usually beyond the skill level of most amateur mechanics.
5/8
Any Auto Parts Store can provide this information. BTW, the are called Freeze Plugs or Casting Plugs, not Frost Plugs.
1 5/8 inch
To change the spark plugs in a 2011 Dodge Nitro, you buy replacement plugs at an auto repair shop. The user manual will list the correct size. Follow instructions on new plugs to install correctly.
6.5 for the front