Hello everyone JC here as a new member. I'm doing a 2026 build on a King Ranch 350 diesel. For 3 months out of the year I'll be doing distant traveling, interstate, mountain areas, National parks, Western US etc. I will have a decent payload maybe up to 2500 to 3,000 (gas and gear) lb on the truck, but no trailer. Other 9 months of the year are going to be much lower capacity (1200-1500) doing short runs some boat trailer (6000 lb). This will be in Florida so not much hills. I don't plan on doing any real off-roading other than some gravel roads but would like to have the best most comfortable ride nonetheless on gravel roads, speed bumps etc. and the truck to handle well on Highway. I consider the FX package but here my thoughts on it.

I don't want the all-terrain tire so I would need to swap them but I'm swapping rims anyway so not a big deal but I won't have the all-terrains. Even if I get the FX I will put highway tires on it

I'm mostly curious about what the performance is on the FX shocks versus standard

the skid plate is nice but likely would never come in useful and it's a little extra heavy weight so I'm good without it

the hill descent and locking differential electronic is nice but again I'll never use it that much.

So my question should I go with the FX and just change tires to highway tires or should I omit the FX package and just upgrade my shocks?

And if I'm upgrading shocks should I go with the fox 2.0 or the Blistein 5100. Again I'm not off-roading I just want it to handle really well on highway and help on gravel roads and potholes on the highways. And I don't need to lift it any more than necessary.

also should I consider steering stabilizer?

thanks for any advice this is my first diesel!

JC

 

I made good use of off road tires in FL. Switching to hwy tires is a mistake, just burn the stock tires. They only last 30k. Nearly everywhere I parked, was loose soil or sugar sand.

I use Fox 2.0's. Youll have to combine those with larger sidewall tires, to smooth out the ride. Carli sway bar.

 

1. Seems you’re focused primarily on ride quality. Why are you choosing a F350 vs F250 ? The payloads you mention above are pretty light duty. F250 will handle that and ride slightly better as the rear spring pack isn’t as stiff.

2. $500 +\~ for the FX package up charge is a no brainer- the A\T tires that come standard are more highway oriented than terrain, they rolled quiet and plenty smooth on my truck, plus you get a little added tread and protection. Locking rear differential is a nice thing to have. Also resale on the FX might be better down the road 🤷‍♂️.

3. Based on your intended use I’d look at 3.31 or 3.55 gearing as well.

 

For earlier years, and I would easily wager for current MY's too, the FX4 package has been a common misconception. The FX4 package does not include AT tires (or locking diffs), it requires them. This means, if you add the FX4 package to your build, the AT tire upgrade, complete with its own charge, automatically gets added alongside the FX4 package. Now, this is also assuming that some other add on, or the AT tire requirement for some other aspect of the truck has not already been met. But, if no other requirement for the AT tires has been made yet, the FX4 package + the cost of the AT tire upgrade is added at the same time. On the same note, the locking rear diff is also not included with the FX4 package, but yet again, it is a requirement, meaning you also pay the normal upcharge for it too. And IIRC, that was almost a $500 uncharge on its own. So, it's not just the $600 cost of the FX4 package to consider, it's also the $500 locking dif plus whatever the AT tire upgrade costs...

For the OP, if he doesn't really want the AT tires, or no other feature of the FX4 package, I would skip the FX4 package. I think it costs $600 now, which will completely cover the costs of Bilstein 5100's, or almost get you a set of Fox shocks. And if you want resale value, just grab some FX4 stickers off EBay for $15. The skid plates are really the only valuable part of the package, and they used to be an a-la-carte option for $100 when building it out. Nothing else in the package really adds anything of value to the truck, but I do agree, it ironically seems like that FX4 sticker will entice more (unknowing) folks.

Also, if the AT tires are still the GY Wranglers with Kevlar... I would just go ahead and swap them out asap. IME, those tires started out not that great, but quickly got even worse. I swapped mine out at 30k and wish I would have done it much sooner. I also swapped the stock shocks and steering stabilizer for Bilstein 5100's around 10k miles in, and with the 5100's and new tires, the truck drove and rode much better. Were I buying a new truck, both tires and shocks would bar an immediate aftermarket upgrade, then list the tires for sale to recoup a little money.

Based on the OP's post, my vote is to skip the FX4 package and spend the money on some good aftermarket shocks. Likely Fox shocks from his descriptions.

 

Here's my input on it:

Stick with all-terrains, OP. Don't put highway tires on it. You are going to be hitting up boat launches, which are notoriously slick. You'll want the extra grip that AT tires can give you. Even at the busiest of launches at steep angles, I didn't need to put any of my trucks in 4WD to pull our heavy tri-toon out of the water. Meanwhile I saw some guys with SUVs and trucks with highway tread on them struggling to get bass boats out of the water in 2WD with their highway tread.

You also say you're going to be spending a considerable amount of time in the western US, hitting up national parks, mountain areas, etc...even in the summer, those areas can and do see snow, and some areas you want to get to might be somewhat off-road. Highway tires do NOT shine in those environments. ATs will serve you better, even if the most you do is gravel roads - I have seen guys need to use 4WD on gravel roads with highway tires because they can't get enough traction in 2WD, while I have zero issues with my AT tires.

I tend to get decent mileage out of my AT tires, my last set went something like 50-60k, and that's pretty routine for me. Sure, there is a slight mileage hit to them, but it's not much compared to highway tires. And they don't HAVE to be noisy to be decent tires.

All that said, I'd consider skipping the FX4 if you won't be doing any serious off-roading. It sounds like there isn't much in it that's going to help you out.

 

The only way to get that kind of payload in an F250 diesel is to get the high capacity axle upgrade, which all but negates the 'softer ride' idea. It still only puts him in the 3k-3300 lb payload range, which would pretty much be maxxing out his payload before people are added to the mix. With an F350 SRW, he's starting at over 4k payload even WITH the diesel, I want to say my Tremor is in the 4500 lb ballpark (I'd have to go look for sure).

 

If I don't choose the FX then they will come with highway tire, I can switch I was going to get the Michelin Defenders. I would think that Highway Tires would be the best choice for lots of road traveling. I'm not doing any type of real off-roading maybe a Forest Road or some gravel road that's about it. What I didn't want to do is get the FX only to find that their shocks are the greatest and have to pay even more to get the what I didn't want to do is get the FX only to find that their shocks are the greatest and have to pay even more to get the fox 2.0. That's why I was leaning towards not getting FX package and spend that money on new Fox 2.0 since I didn't see the need for the a/t tires.

 

I felt that going with the 350 would be worth it for resale as well as having plenty of power and low capacity if I ever did want to tow a heavier trailer which is a possibility but not any guarantee.
2 FX package seems like a good deal but I didn't see it quite as worthy for my uses especially if I'm going to need to further upgrade the shocks on delivery to Fox 2.0 or the Bilstein 5100.
3 I originally considered the 355 because it's a more heavy duty package but wasn't sure if it would be the best ratio for lots of highway driving with just heavier payloads rather than towing a trailer.

 

That was one of the first things I did, remove that stupid FX4 sticker....

To the OP, I pull a 14K 5th wheel all around the country and I have 3.31's....... no issues

 

For your usage, I'd skip the FX4; the shocks are no great thing from all reports and the other stuff you won't use......and the skid plates reduce payload a bit as well. If you want to spend the money, I'd buy better aftermarket shocks.

Dave

 

Yes it seems for my mission is looking like: skip FX, order 3.31 w/EDL, buy shocks (Fox or 5100s), and run with the Michelin Defender LTX M/S 2. I'm thinking this will be a nice ride.

 

You need the skid pkates. The fuel tank is very vunerable due to our wheelbase. Fx4 shouldnt be an option at all. It should be included in the base.

Id absolutely get Fx4, elocker. And upgrade to Fox 2.0's immediately.

 

I wouldn't buy the FX4 package just for the shocks. In my opinion, all of the factory shocks are sort of 'meh'. They're OK, run them for a bit and see if your feel an upgrade is worth while, then swap in some new shocks. I'm 20k in on my factory shocks and they're starting to show signs of giving up. Next year, I'll likely swap to Fox 2.0's. I like them slightly more over the Bilstein options because I've found Bilstein shocks to 'stiffen up' as they age. They ride great when they're new, but then the ride quality seems to deteriorate with mileage and use.
The FX4 'AT' tires leave a lot to be desired. They weren't great on wet roads and I didn't keep them long enough to see how they did in snow. I swapped to an older wheel/tire set from a '19 F250 with Michelin AT2's. A few fleet guys around me have nothing but terrible things to say about the non-AT Bridgestones that their XL work trucks came with. Good on dry pavement, but any water or snow and they seem to lack for traction. Since you're swapping tires anyways, that won't really be an issue regardless. I'd sell off whatever stock wheels and tires you get and fund some decent shoes for the new truck.
The locking differential is nice and can get you out of trouble in a pinch, but you can get that without the FX4 package. The 'off road' skid plates that come on the FX4 are not real skids. They may help you slide off something but if you put the weight of the truck on them, they're going to fail. Light off road, they'll protect from small sticks that kick up (maybe), but they're not real skid plates and shouldn't be viewed as such.

 

I just bought a 2025 F350 with camper/plow package (ccsb) and when road testing drove it back to back with a F250 ccsb FX4. Since I am coming from a f150 I was paying close attention to the suspension as I was afraid that the f250 would be too stiff, I found that even the f350 with uprated springs for the camper were fine. Yes it was firm but not a sharp kick in the pants more of a shove.

The FX4 f250 and F350 with stock shocks (when new anyway) were almost the same over sharp edged bumps, I was aiming at every pothole, train track, frost heaves and manhole cover I could find. no slowing down trying them in a straight line and mid corner. I was impressed with both and did not see a benefit for me to go with the FX4 truck, one of the benefits to the superduty is the ease of changing a simple shock, If my cheap oem shocks do not last I will happily put on something that will last better but I would be skeptical that it would dampen better.

 

I'll let you know when we puncture one of our fuel tanks......but don't hold your breath. ;-)

Dave