Ignition
Some specs and stuff, don't forget the subpages below.
Pancake Distributor Disease(GM Vortec Engines)
Quality spark plugs last longer, that's really the main difference in the types of plugs. As long as you are using the correct plug/range you will be just fine. If you have engine running issues, like coolant or oil being burned through the cylinders they are not going to last as long or at least require more frequent cleaning.
Don't use anti-seize or lubricants on your spark plug threads and don't be a chump use a torque wrench.
Use the best quality plugs and wires, esp with a stock van as they are not the easiest plugs to access/change on these vehicles.
Access though the wheel well can help for some of them, esp if you already have a body lift in the front.
Always start the threads by hand or using a short piece of hose/tubing so you don't cross thread the plugs.
Always use dielectric grease on the plug wire boots to create a good seal and so they don't stick. A little goes a long way.
4.3v6 firing order: 165432
Spark plug wire resistance 800-1000ohms per foot, ya know, depending.
Spark plug types and gaps
2003 - AC Delco R41-932 gap @ 1.52mm(0.06in)