I have a 2006 Uplander w/3.5L engine. I changed the plugs & wires @ 90K. Used the factory AC Delco. Immediate difference noted in starting and running smoother. Pulled the engine forward to change the rear plugs. It is difficult but can be completed. I had to "feel" my way around the rear of the engine & most of the wires were sacrificed to remove after 90K miles. Good Luck with your Uplander!