35" or 37" tires on a DD F350 or Ram 3500

[Fish]

The Carli and Thuren coils are softer than the stock rates. They may be too soft for hauling your cabover. Serious damping would help a bunch too. The stock shocks are designed to deliver a soft ride to convince the prospective buyer to buy.

For what it’s worth, I have the Thuren 0.5” soft ride springs up front on my RAM 3500 and have been carrying around my Lance camper for 8+ months now and have no complaints about any payload impacts. Paired with the King 2.5” shocks they’ve performed well both on and off road.

Just ordered a set of Thuren 1" springs for my 2018 2500. They're the same as the 0.5" springs for the 3500. I haul a 720 lb Callen camper every day and have a small trailer, so I'm keeping the stock rear springs. Sounds like what Adventurous did as well.

Also ordered King 2.5" shocks all around. Don has a special tune for stock rear springs. He's also got a new "Stage 2.5" tune for folks like us. And he had them in stock, so they shipped the next day.

All of the above was discussed with Don via email and those were his recommendations, along with a front track bar. He's pretty responsive via email, so give a shout if you don't believe us or want to special order the Stage 2.5.

To answer your original question, I've run 315's or 35's on my '07 2500 for about 100K with no major issues. Ride is much better than stock. I'm running Carli coils, Thuren King 2.5's Stage 3 (front) and 4 (rear), and Deavers with Thuren shackles in the rear. The Deavers do squat with weight, but it was totally level with the Callen and Thuren shackles. I'd think about air bags on mine with a Lance. Oh.... and you could solve your dilemma by just buying my '07.

 

[Adventurous]

Since @Fish mentioned airbags, I’d also like to add that my truck required airbags with the camper (dry weight: 2,400 lbs, loaded weight maybe 3,000 lbs). Additional details are tucked away in my build thread, but I’m running Air Lift bags with Daystar cradles and have been happy with the combo.

 

[TexasSixSeven]

I’m running 37x12.50s on my 17’ F-350 with a stock suspension. I can’t see going 35s on these trucks. I lost a little mileage and acceleration at first, but deleted it and gained it all back. It drives as well as it did stock.

That’s 21k behind me. Truck is barely squatting 1” below level. Normally sits 2” above level in the rear.

 

[Regcabguy]

35's here. To be honest I might return to LT metric tires,maybe a 305-70-18. Tall and skinny.
First photo is a friend's qcsb with Northstar.
Monument Valley shot is mine.

 

[mep1811]

I would think which tire can you easily change , pick up and lift into the pickup bed on your own .

 

[Fish]

35's here. To be honest I might return to LT metric tires,maybe a 305-70-18. Tall and skinny.
First photo is a friend's qcsb with Northstar.
Monument Valley shot is mine.

Yes, I think I'm going to do the 305-70-18 on my new truck. Higher weight rating that matches the truck a little better. Thinking Cooper ST MAXX.

I'm really tempted to put 37's on it, but then I run into a spare tire issue as @mep1811 pointed out. Not sure if I'd feel comfortable with a 35" spare on 37's. Not sure the look and ego of 37's is what I need.

Also debating if I should switch from 3.42's to 4.10's with a 35. Something else to think about with your plans, OP.

 

[Explorerinil]

35's here. To be honest I might return to LT metric tires,maybe a 305-70-18. Tall and skinny.
First photo is a friend's qcsb with Northstar.
Monument Valley shot is mine.

Why the switch?

 

[Explorerinil]

Yes, I think I'm going to do the 305-70-18 on my new truck. Higher weight rating that matches the truck a little better. Thinking Cooper ST MAXX.

I'm really tempted to put 37's on it, but then I run into a spare tire issue as @mep1811 pointed out. Not sure if I'd feel comfortable with a 35" spare on 37's. Not sure the look and ego of 37's is what I need.

Also debating if I should switch from 3.42's to 4.10's with a 35. Something else to think about with your plans, OP.

I guess it really depends on what you do with your truck and where you take it. Here in Illinois I like the larger wider tire for the clay mud and rutted up farm roads/seasonal roads that I take often, espically durning hunting season.

My truck is sitting in my garage right now covered in mud from taking down my deer stand, a short narrow tire would mean I’m hiking in to take it down.

 

[Regcabguy]

Why the switch?

I don't really need a flotation tire as I don't hit sand much. It's going to be awhile as the switch will require 18" rims,
Are you still considering the AEV's?

 

[Explorerinil]

I don't really need a flotation tire as I don't hit sand much. It's going to be awhile as the switch will require 18" rims,
Are you still considering the AEV's?

I got yah! Considering? I’ve been running them for 3 years. I’m not sure I know what you meant.

 

[hemifoot]

i only run my general grabber flotation 35's in the winter.i get better response and mileage from my metric 35 equivalent ridge grapplers when my camper goes on in the spring till late fall.tried 37's and took them off after 1 week.they rubbed even with the inners trimmed and i wasn't about to cut them back further.plus i prefer the 20" rim and slightly narrower tires for carrying the camper.

 

[Tex68w]

I have had Super Duty's with 35's and 37's and a Ram 2500 Power Wagon with 37's and IMHO these trucks don't look right with anything smaller than a 37. That said, if the trucks main purpose and goal is to be worked and tow and haul heavy loads, then a 35" tire is probably the right choice for the sake of maintaining factory numbers in regards to the power, torque, and payload. With all of that said, I now have a hard time seeing a 37" tire as big on these trucks and constantly find myself wanting another on 40's lol. It's a sickness.

 

[billiebob]

Assuming you have gearing which will work, I think the only real issue will be shocks. 37s will add considerably to the unsprung weight. I'd include a shock upgrade too.

 

[Big50]

25k miles on 37x12.5-17 Falken MT's. Rides great and could barely tell any difference. With 925lbs of torque it still pulls like a freight train and rides great.

 

[Buliwyf]

Sheesh. How much cv angle can an f150 handle?