'88 Cutlass Ciera 3.8 hesitates under acceleration

My friend has a 1988 Cutlass Ciera 3.8 that bucks and hesitates when accelerating from a stop light. The cutting out and hesitating increases as you press further on the accelerator. When the pedal is pressed only ever so slightly (under very, very slow acceleration) the problem is minimal to nonexistent. Once the car gets going it runs just fine and the engine idles and revs smoothly in neutral as well. I thought many things could be the problem, from fuel filter to sparkplugs/wires, maf etc. Today I noticed that the car does not have these symptoms when in reverse: the car does not cut out or hesitate no matter how quickly I accelerate in reverse. Is the transmission going? What could be the problem?