bjorkmae, what you saw is simply a 98 ClubCab 12-valve.
Dodge sold these trucks (beginning in 98') with either the 2-door (ClubCab) or 4-door (QuadCab) entended cabs.
Rumors are they did this until 2000, for some reason.
I have only ever seen ONE 1999 24 valve with the ClubCab (2-door).
So they phased out the 2-door cabs over those 2-years but if you go looking for 98 12-valves you will see a somewhat even mixture of 2-door and 4-door trucks.
Go on Autotrader and look. You'll see plenty of both styles.