Firing order is 1,2,3,4,5,6 the correct numbers for placement is on the coil so it would be wise to take off one spark plug at a time
What Is The Firing Order For The Coil Pack On A 3.5 Liter 1996 Dodge Intrepid?
They didn't make a 3.5 for that car so I assume you meant 2.5 liter. It 1-2-3-4-5-6-on the coil pack