Perhaps you mean 81-93? 94 was a completely new body style. Most of these did not have Magnum engines or fuel injection. See WO23Coronet's post on when the Magnums came out. The LA engines had TBI fuel injection in 88/89 (318/360). I'm not aware of any Ramcharger having rear discs either.

4WD trucks didn't have disc brakes on the front until 1975, except I think the Ramcharger had them in 74. The 75-79 trucks were full time 4WD and the front axle is the least desirable axle of all generations of Dodge trucks. The 2WD trucks had discs standard in 73 but optional in 72.