My 98 E-350 V-10 is at 95K miles, so I'm just about ready for this change too. I know the pick-up guys complain about one plug in particular in the back, but we vanners should not have that particular problem. I can't imagine paying more than $5 each for plugs, and some people say to replace the boots also, which can't be too expensive. The single MOST important thing is to make SURE to get the new plugs torque'd properly, and that you use some thread lube on your new plugs. The V-10 has very few threads in the spark plug holes, so proper torque is mandatory. The thread lube just helps prevent galling between the steel plugs, and the aluminum heads. Some dielectric grease on the boots will help prevent misfire in the future. There is one plug on the V-10 that sits right over a coolant connection. If you have a small leak over that plug it can erode the metal around the plug and cause spark plug blow out. But I'm going to change my own plugs. The doghouse coming off has got to make it much easier than opening a hood. But I went through a major headache after putting plugs in a Zetec Ford. Unbeknownst to me I was cracking the insulators, which would cause a misfire in a couple days, it drove me and the dealership crazy until we figured out what it was. The torque amount is critical. Make sure you have a plug wrench with the neoprene protector, and go slowly and carefully when you're fishing the new plugs down into the hole. You can do it ! (when you're done, post here so I can do mine) Take care, good luck, Ken