If you can, work with him, it's always good to gain some experience and knowledge under the hood and that can save you a boatload of cash in the long run. I learned most of what I know about working on cars by being a young broke guy with a frequently broken muscle car and having others with similar past experience help and guide me through it's many repairs.
Yes, Motorcraft does market all the parts for the job, but we have found that their OEM manufacturer is actually Denso and they also sell under their brand for less than the MC stuff is typically.
Plugs - Motorcraft SP-479 (These are the plugs you want, ignore all others! )
Boots and springs - Denso Part # 671-0001 for a set of 10. (always change the boots and springs along with new plugs).
COPs - Denso Part # 673-6000
Ensure that your guy uses a dab of dielectric grease on the spring ends, this will help to reduce any corrosion their which leads to resistance and a future possible miss.
Never-seize on the new plug threads and tapered seat.
On your '03 the factory plug torque spec was only 17 ft/lbs, (not very tight), many DIY owners here have increased that with good results, I torqued mine to 32 ft/lbs.
Here is my thread on my plug change. https://www.ford-trucks.com/forums/1...ug-change.html

I do advocate that folks should not "Fear the gear", but if the long range plans are to stay with stock 31.6" tires then 4.88s may be too much of a good thing. I did run 4.88s and 32"s for 2 years, but my rig see nearly all of its miles towing heavy, which that combo did great, but it did carry a bit of an economic penalty in that it lost 2+ MPG in unloaded use. In your other thread you mention both 35"s and 37"s, its very, very important to finalize your eventual goals BEFORE spending the money and committing to new gears (and a lift). An effective gear ratio in the 4.30 to 4.56 range is the sweet spot for these rigs based on everything I've read and my personal experiences to get great performance without too much downside, that stock tire & 4.88 combo may be tipping the scales a little too far in one direction.

 

Thanks guys - your replies are always so generous.
I have a scanner on order actually. One that reads Mode 06 too. Only cost me $60 and I figure it's worth having.

Are you using an electric or air tool in your post, Tom? I found this, but I'm not sure the Ft/lb is adjustable... https://www.homedepot.com/p/Milwauke...-20/203111681?

Something like this could make all the difference and is the same price as getting my guy to do it...

Also, it's only really necessary to replaced the boots and springs right? The COPs themselves are okay to go another round? I know you mentioned buying two new COPs, Tom, but it was the tab of the wiring harness that broke (I have ordered 8 new ones for $10 and discovered how to swap them out without cutting and splicing)

 

The only tool pictured in my spark plug thread was my trusty old clicker style Craftsman torque wrench (and a little plug gap disc), what you linked to is a battery powered ratchet wrench, two completely different animals. I do have an assortment of air powered tools and a few cordless electrics but typically they stay in the box and I use all hand tools for most vehicle work.
You should be able to find a decent torque wrench and a 3/8" ratchet and socket set for not much money. Harbor Freight hand tools are fine for the DIY crowd, I use plenty of them. I used the GearWrench 80546 5/8"X6" wobble spark plug socket, it makes access much easier along with a few additional extensions for the farther back plugs.
Yes, boots and springs should always be replaced along with new plugs. COPs should last a long time and are either good or bad, I see no reason to replace a good COP, but I do keep 2 new spares on hand if one of my factory ones ever fails. I suggested 2 COPs for you, 1 to replace the #9 if the new plugs and boots don't restore the cylinder to where unplugging the COP causes a noticeable change.
Glad you found the replacement plugs, good luck swapping them out.

 

Ah, okay. Gotcha - it looked like an electric tool for sure!

Walmart sells the Denso COPs at a hair over $17 a piece. The plugs are $3 a piece. With that in mind I could do an overhaul at $200 in parts and my guy is charging me $120 for all ten plugs to be replaced.

I want to do it myself (I'm that way inclined) but I think I'd rather get him to do it - especially in this weather

UPDATE: All 10 SP-479 plugs are ordered as well as 10 shiny new Denso COPs (@ $175 for the COPs I figured it's better to do the whole thing in my instance, as opposed to just the boot and springs)
Pads and rotors after this, then considering that gear swap and an SCT tune

 

 

I think that the addition of the dab of dielectric grease to the spring ends will help to avoid that kind of contact corrosion that you had.

 

Here's a consolidation of what's been done so far:

1. Fixed ESOF system. Tested the lines for the hubs on up with a vacuum gauge. Got all the way back to the PVH solenoid so replaced that and now back in business - so running auto hubs now.
2. Fitted a locking fuel cap.
3. Ordered 10 Denso coils and 10 SP-479 plugs. Replacing them next week (after unplug test was inconclusive on two plugs)
4. PSI on all four tires to 55 PSI based on Goodyear garage's advice before they performed a...
5. Wheel alignment check (results were dead-on, so wasn't necessary to continue)
6. MAF & throttle body cleaned.
7. Two 16oz cans of Seafoam ingested.
8. Injectors "sound checked" via stethoscope. All click-click-clicking as they should (although not checking them off the list just yet)
9. Cursory check for fuel leaks underneath. Nothing found.
10. Bought scanner and will be looking for codes when it arrives sometime tomorrow.

I think that's about it so far. Next steps after plugs is to replace all brake pads and rotors. I know the rear pads are at 50% life (front is about 80%) but I'm swapping out to Hawk LTS and Frozen Rotors (although they are very expensive it would seem). I want the stopping power I've never had in this beast and on these roads, you need all the help you can get.

Since last fill this tank has seen a slight improvement as roads were much clearer and less 4x4 time. I'm currently sat at 185 miles with needle slap-bang between 1/4 and 1/2 tank.

More soon.

 

i'm pretty sure i did that when i installed my 10 new ones. but it was pretty much a year ago so I can't remember now. but it is good advice for the OP

 

i would be surprised if your 2 that were inconclusive were firing, there was either a distinct change or not.

make sure you check/fix the gap in the center of the cowl, there is a few threads in the tech folder. I like many others also had the problem and it was making 9 &10 wet

 

Good tip. I'll order some silcone gasket maker. The thread mentions using a piece of plastic to bridge the gap, but the Permatex sealent should be enough right?

 

 

EX has been scanned.

"No fault codes found on this vehicle"

 

 

 

What is this? Salt in the wound?