Well I service vehicles locally and one of my customers has a Dakota but its the V6 (3.9L I believe). And I service it from front grille to rear bumper for him. I wont say its a completely easy job but its no harder than doing the plugs in the Grand Prix. The V8 I can see being slightly more difficult because I would think it is recessed more in the engine bay.

Ive serviced some older Ford Expeditions with the 5.0L V8 in them and you have to get to the spark plugs down through the wheel well area and I would suspect the V8 Dakota is probably going to be a similar thing, but Im not speaking from experience so take it for what its worth.