PM Beau (rbr2328) and he can supply you with the Ford part numbers. You'll need front springs as well as rear blocks and the longer U-bolts. The Ford parts are going to cost less than an aftermarket kit and work better.

Put airbags on while you're under there- you're doing half the work anyway and if you're towing much over 4,000lbs it makes a huge difference. Use the Excursion kit (I prefer firestone's). You have to remove the stock bump-stop rubber from the frame. Before you install the F250 spring blocks, cut the bump-stop ears off with a cutoff wheel. The airbags don't clear them with the taller blocks. I mounted my pump in the jack compartment in the right rear of the cargo hatch. I took the gauge & switch from the bracket and mounted it in the compartment door panel. Now I can adjust height when hooking up the trailer. I took a piece of broom handle and made a bumper-height gauge with it. Now I hook up, pump up and set it to the unloaded bumper height. Remember the Excursion hitch needs a WD setup over 5K.

Think it was CS who gave the tip on my power loss and cloud of smoke problem awhile ago. It was a good hope that valve thing came off, something about pollution control! Well it did disappear and over a year latter, zero problems with 6.0 PSD!!!!

I'm going to investigate having this better handling. Despite having over 150K miles on mine and its getting pretty trashed inside. I don't think can get a better SUV for space, towing, and transporting 3 Rottweilers. Bought it just before 05 with 9 miles on it. My previous one wandered like this as well... It's always been a small annoyance of mine with these, until I get adjusted to driving them. But sometimes do think that one day I'll get pulled over for suspected DUI and that will not be fun with my dogs inside! They'll scare the chit out of any one that gets close while inside their Excursion! One has even busted out the rear side windows!

The EGR sticks in 15K. Most of the time they're ruined from the sticking. You can do the "work-around" or you can have a truck that doesn't run as well as it should. Or you can replace the $600 valve every other oil change. I'm surprised the EPA hasn't dinged Ford on this problem.

The wandering took me a while to get used to. I think it was just different from my Denali. I tow my boat just fine with mine but I put a 35 Cig on the back and it was almost doing a wheelie.... the tires pressure is important, i checked mine and it was way off, evened them out and it made a huge difference. Also could be the alignmnet is off.
I know GLH pulled his 42 Cig to Key West a couple times with his Exc. and he had airbags and a couple other smaller mods and it did fine but I am pretty sure he will tell you his dually is like night and day from the exc.

I pulled a 35 Cig from FL to OH with my Ex.

Bags, shocks, bars, F250 springs, WD hitch, upgraded brakes, you name it. A very comfortable, relaxed trip. The 42 would have really been pushing it- and well beyond both the tow rating and the hitch's capability.

If your nose is pointing skyward, your alignment is going to change.

Ok Ford part #'s for the X spring set up which is the fronts used on a F450 and F550 are
Springs-2C3Z5310AF same for left and right
Blocks-F81Z5598FA and F81Z5598GA one is left one is right
Ubolts-F81Z5705EA you need 4 I think part# is for 1

What about f 250 series.Called another 4x4 place today and told them about the wandering,they said no springs wont help! Sure sounds like they would.My sterring wheel moves back and forth without turning the wheels and I think thats a problem right there.At least 2 inches either side when I rock it.I too think Im going to get pulled over for DUI the way the thing drifts.If you dont pay attention your in the next lane!

What is the wd hitch? and what upgraded brakes did you use ? I have the Bags, Shocks, Rear sway bar now , looking to do the springs next Thanks

Sounds like you may have a broken spring, worn out steering or a worn or broken trac bar.

Working around has made the engine trouble free..... I'll look at your suspension upgrades.

No wondering will make this thing perfect for hauling cars, boats and dogs.........