Decisions.....Decisions.....35's or 37's??

ih8minimumwage

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My current wheels are Backspace 4.500.....Offset -12.....Diameter 16.....Width 8

I will be going with Backspace 4.500 or possibly 3.750 or even 3.500.....Diameter will be 17, and Width will be 9.....I am not sure what the offset will be yet.....but if I go with the 4.500 Backspace they are -12.....if I go with one of the others I'll have to check and see what they are.
I went with the Pro Comp 51-5981 wheels (17" with 4.25 backspacing) and 37s and have no rubbing. That's on a stock F350 suspension. Finding anything decent for 16" wheels nowadays is no fun.
 

u2slow

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I was more getting at 35" being a comfortable/practical/affordable limit.

I find myself taking the 2wd for firewood chores when terrain allows. Not the most fun lifting heavy rounds up 40"+ into the bed.
 

Clb

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Ok next dumb question...
What's the reason for the lift if a 33-35" works fine as is?
low cog rules in the crawling,carving corners world.
Sorry looks like I'm to dino to be relevant...
 

Thunder_God_69

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OK, so the reason for the lift is because I primarily use the truck off road.....the leaf springs on it now are STIFFFFFFFF ASSSSSS HELLLLLLLL.....I ordered a pair of Alcan off road leaf springs. As you know, stock style leaf springs are pretty much flat in the front, no curve.....the off road springs DO have curve up front, there are several reasons behind this which I will not go into here. The bottom line is that the curve is obviously what is providing the lift.....it is 3" higher than stock up front.....and I opted for 2" higher in the back to maintain most of the rake for the times when I am hauling firewood and things like that. The truck is going to have a really nice look to it I feel, and it will have a MUCH BETTER ride. I am simply looking to go with the biggest tire that I can get away with and not loose much drivability.....I know a 35 would be fine.....dropping 100rpms is barely going to be noticeable. I can crawl in first gear 2WD when pulling out and not even hit the throttle.....and I can roll along at a walking pace almost, it's ridiculous. The 37's may be pushing it in certain situations, but if I can get away with them, I will.....bigger tires make bumps and what not seem small off road, and provide more axle clearance. If I were going 70mph, I would still be turning close to 1800rpms, which I see nothing wrong with.....I feel like I would use 4th gear maximum when on back roads going up to around 50-55mph.....and on the highway I'd grab 5th and the motor would barely be working.....if I had the bed loaded, I might need to stay in 4th and go slower.....I'd probably even need to shift down to 4th when empty on some hills if I let my speed drop and got out of the sweet spot in the RPM's.....but I really don't see the big deal there. I mean, am I wrong.....does anyone else think this sounds reasonable??
 

sjwelds

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Just as a data point, my truck with stock Ford Alcoa aluminum wheels and 285/75/16 hankook dynapro ATMs hit the springs at full lock through a dip. I put a 1/4" spacer on and that made just enough difference.


I would not go bigger than 35" tires. Remember there's more to it than just lower engine rpm....the higher you go the more wind you push, and bigger tires will take more power to turn..... among other things.
 

lotzagoodstuff

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My old red and white truck was pretty similar to your truck, but with 4.10 gears. My injector pump and injectors were very new when I got the truck and I think it ran really well for a normally aspirated IDI. IMHO, 37s are too much with 3.55 gears. My truck was fine around town, but point it towards a pass or hook up the car hauler/racecar, and it struggled. That was with 4.10s. There are some IDI trucks that can pull off 3.55 gears, but they have pump work, turbo, and an intercooler.

Mathematically you will have lower RPMs with a taller tire, but the wind resistance, lack of low RPM torque in an IDI and the actual increased weight of the tire are all competing against you. 37s will look great, but going bigger than 35s will hurt driveability, clearance, and fuel mileage versus 35s

By the way: welcome to OB! Fill out your signature so we know the details of your truck and your general location.
 

Thunder_God_69

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My old red and white truck was pretty similar to your truck, but with 4.10 gears. My injector pump and injectors were very new when I got the truck and I think it ran really well for a normally aspirated IDI. IMHO, 37s are too much with 3.55 gears. My truck was fine around town, but point it towards a pass or hook up the car hauler/racecar, and it struggled. That was with 4.10s. There are some IDI trucks that can pull off 3.55 gears, but they have pump work, turbo, and an intercooler.

Mathematically you will have lower RPMs with a taller tire, but the wind resistance, lack of low RPM torque in an IDI and the actual increased weight of the tire are all competing against you. 37s will look great, but going bigger than 35s will hurt driveability, clearance, and fuel mileage versus 35s

By the way: welcome to OB! Fill out your signature so we know the details of your truck and your general location.
You make some very fine points.....and overall I am convinced to avoid the 37's.....I wish I could run them, but I am definitely not gonna tear into the axles for only that reason right now, I recently put on new diff covers, changed the fluid of course, and have them sealed back up real nice. Everything looked VERY good inside both front and rear as well. If I went to 4.10's or 4.30's I would also want to do lockers, and I don't want to put that kind of cash into the axles right now. Also, the truck does run VERY good.....I am actually very impressed with how well it runs, it's kinda crazy to be honest, with that being said, I'm still going to reluctantly shy away from the 37's. Now I must ask.....do you think 35's will be alright?? I mean, I don't think I'll actually notice much of a difference to be honest.
 

Clb

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Well the alcans have some reputation in the off road community, hopefully on an idi they work. Unfortunately a LOT of "lift kits" have overly radical arch to make the lift and thus ride stiffer.
Same issues a flat spring rides better and flexes farther due to going negative but doesn't love to suspend weight quite as well.
Honestly, a man can get used to ANYTHING...
The "need" supersedes the want of stock reliability/comfort/functionality.
If you can deal with the loss of grunt (and you are giving away grunt with every mm of tire you add width and height) and it makes life easier do it.
Just know jumping outta the lifted truck gets kinda old and becomes a pita for dd duty.
Going from a 31" tired crawler to a 37" one made the same trails way easy, so I get it.
 
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Thunder_God_69

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I know it's been a LONG time since I posted.....but one thing led to another.....and I ended up spending A TON more money than I planned. I basically rebuilt the entire suspension with far superior parts. Decided to go with the 37's.....and with all the extra work I did.....it drives way better than it did before, and it even has more low end get up and go, as I upgraded the gears, and went with 4.10's from the 3.55's it originally had. I considered 4.30's.....but ultimately I think I made the right decision. The truck cruises down the highway very nicely, at a decent RPM.....and has PLENTY of grunt at low speeds. She is still a work in progress, but she is coming along nicely. Let me know what you guys think so far.
 

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Thunder_God_69

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Big clean truck, the 37s dont look like 37s on it. Details on the wheels?
Thanks man, I've been working ******* it. I could have easily cleared 40's, but I wanted room for articulation.....and I actually feel like the 37's give it a really nice look. Anyway, the wheels are Method 108 Bead Locks in Matte Black. They are 17"X9" with a -44 offset, backspace is 3.50. I really like the look they give it.....not to much poke, and not to little. They are a real bead lock on the front side, and a bead grip on the back. Twenty four 3/8" grade eight bolts for hardware. I balanced them with 16oz of Counteract Balance Beads per tire. Unlike airsoft beads, or BB's.....they are TINY polished glass beads, that actually hold a static charge, and DO NOT hold moisture, or clump together. I can drive down the highway at 70+ MPH and the wheel is GLASS smooth. No vibration felt in the wheel at any RPM or speed, other than normal IDI motor vibration LOL. I could not be happier with them.
 

hacked89

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I agree they look good thanks for the details. Considering the money on beadlocks do you go off road? Saw your PA plates, I go to rausch creek often but the trails are tight for 3/4 tons.
 

Thunder_God_69

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I agree they look good thanks for the details. Considering the money on beadlocks do you go off road? Saw your PA plates, I go to rausch creek often but the trails are tight for 3/4 tons.N
No worries, the bead locks are soooo worth it man. A lot of people will give you hate and say that they are dangerous, blah blah blah. If you follow a very specific mounting and torque procedure, they are not dangerous in the least. I do go off road, that is primarily what I built the truck for. I don't plan on doing any REAL extreme stuff with this rig, as I don't want to destroy it. Meaning that if I think to myself, ummmmmmmm that looks like it's probably gonna be really expensive, I'll usually find an alternate route. Like you said, many areas are just to tight, and I don't wanna tear up my sheet metal. If you get a set of bead locks, I highly recommend these ones. I did a lot of research before I pulled the trigger on a set. Also, I'll be happy to share the torque procedure that I learned from the guys at method, it really worked great for me while mounting things up.
 

asmith

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I know it's been a LONG time since I posted.....but one thing led to another.....and I ended up spending A TON more money than I planned. I basically rebuilt the entire suspension with far superior parts. Decided to go with the 37's.....and with all the extra work I did.....it drives way better than it did before, and it even has more low end get up and go, as I upgraded the gears, and went with 4.10's from the 3.55's it originally had. I considered 4.30's.....but ultimately I think I made the right decision. The truck cruises down the highway very nicely, at a decent RPM.....and has PLENTY of grunt at low speeds. She is still a work in progress, but she is coming along nicely. Let me know what you guys think so far.
Nice looking truck, I like the color and wheels. the 37s turned out good.
So did you stick with the ALCAN springs? what else besides gears did you do to the suspension and axles?
 

Thunder_God_69

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Nice looking truck, I like the color and wheels. the 37s turned out good.
So did you stick with the ALCAN springs? what else besides gears did you do to the suspension and axles?
Oh man, where to begin, lol. I pretty much rebuilt, and overbuilt everything you possibly can. Went with the custom ALCAN springs, they are AWESOME, by the way. Everything else is pretty much from Sky's Off Road Design. Shackle flip in the front was achieved with Sky's 2" RFK kit with custom shackles, shackle flip in the rear was achieved with Sky's spring hanger and rear shackle flip kit, the spring hangers are their 5" models, they pair perfectly with the front 2" RFK kit. Total lift in the front is 4 1/4", total in the rear is right around 6" to 6 1/4", when you factor in the springs. Went with Sky's dual shock towers in the front and fox shocks, new U-Bolt plates for the dual shocks, new U-Bolts, and all new hardware. Custom rear blocks with overload tabs from PMF in the back, went with 3" blocks down from the factory 4" blocks, wanted to achieve as much of my lift as possible through spring, spring hanger, and shackle flip. New 3/8" thick top plates and 3/4" thick U-Bolts both from PMF. Fox shocks in the rear as well. Extended brake lines all around. Fully rebuilt both the front and rear axles, all bearings, races, and seals replaced. Went from the factory 3.55 gears to 4.10 gears. Did a Yukon master rebuild kit in the rear diff, as well as Yukon ring and pinion, and an Eaton Detroit Truetrac locker as well as a Ballistic Fabrication 3/8" thick welded steel diff cover. Did a Nitro Gear master rebuild kit in the front diff, as well as Nitro Gear ring and pinion. Went with Nitro in the front instead of Yukon because they offer a slightly upsized ring gear that is stronger than stock, the quality was amazing, every bit as good as Yukon. Once again, did an Eaton Detroit Truetrac locker in the front diff, and a Ballistic Fabrication diff cover. Also upgraded the steering to the Carrick Customs Dana 60 OBS HD Steering Kit, it is MINT. I feel like I am forgetting some things, but you get the idea. I am debating going with a set of traction bars from either Sky's, or Carrick Customs.....I just want to speak with them, and see it it will make my ride harsher. The truck rides like a dream right now, and is amazing. I would like to run the traction bars if possible, to minimize the wear on my rear springs, as well as eliminate wheel hop that I get under certain conditions. Not sure if the bars would be a problem off road, but I am thinking not, because of how they are designed. I really did my homework, and I was more than pleased with the result. I had it built up in my head that it would turn out pretty damn good, and it exceeded my expectations for sure. Oh, I also did a custom front driveshaft from JE Reel Driveline, it's a double cardan with 1410 yokes.....MINT
 
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