How many quarts of oil does a 1998 Dodge pickup take?

As many as it takes. In 1998, Dodge pickups were available with a 3.9 liter Magnum V6 (1500 only), 5.2 liter Magnum V8, 5.9 liter Magnum V8, 8 liter Magnum V10 (2500 and 3500), and 5.9 liter Cummins 6BT diesel (2500 and 3500). Each engine has different oil capacities, and we have no way of knowing which one you have without you telling us.