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Discussion Starter #1
Has anyone yet tried different springs between the gasser & diesel F350 front leafs? Was there a noticeable difference, as in ride or travel. Given one ton springs will only flex so much I would just like to hear more about the difference.

Believe me, there is a reason to the madness in my inquiry. I will answer soon enough........:popc1:
 

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I was wondering this too. PSMWRX doesn't seem to think there is much of a difference in the springs and he used 460 springs because of a swap he planned. I want to find a set of 351 springs just to make sure and get the flexiest I can.
 

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I don't know first hand if the 351 or 460 leaves are different. I used the 460 leaves as I plan to put a 460 in mine by the end of the year like muddyjack mentioned. If ford did in fact use differnet springs per engine (you guys know better than me) I would think the 351's would be a softer ride, but as for flex..... Ask Andy351, he seems to have the leaf info down pretty well.
 

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A lot of leaf guys here like to run rear 1/2 ton springs up front. The 302 springs where a little softer. I sold the pair I had to a guy that built pulling trucks, said they run just the main leaf and reengineer the front suspension to prevent wheel-hop.
 

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Discussion Starter #6
A lot of leaf guys here like to run rear 1/2 ton springs up front. The 302 springs where a little softer. I sold the pair I had to a guy that built pulling trucks, said they run just the main leaf and reengineer the front suspension to prevent wheel-hop.
Right you are, but also a lot of guys here also run the 1 ton springs and then of course there are the 52" blazer springs, also cant leave out the other options such as some who run the re-arched 77-79 super cab springs. The options are endless, Of course there some of those guys who ran the stock rear springs in front switched back over to the f350 front leaves because they werent happy with the stock bronco springs in front (just some of them,a lot of guys have stuck with them too). I would rather just get a little info on the various spring rates of the f350 springs
 

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When it comes to leafs there are endless possibilities. The reason for this is because leafs can be mismatched, re arched, and cut. It all depends on what you are looking for, how your rig will be set up, and what your plan on doing with it.
F-350 leafs- Some have had pretty good luck out of them however they tend to be pretty stiff and don’t flex all that great when compared to other leafs. However there seems to be a fair amount of them available that people can get their hands on so that’s why they are chosen. On the street (and remember this is what I have heard) they actually ride pretty decent. Since they are also a flatter leaf that is on the stiff side you tend to get less bump steer out of them.

Bronco leafs- While they are 1/2 leafs and seem to work well on the bronco's that are running them around here, they tend to cause a fabrication nightmare because of the offset pin. In other words the pin is not in the center of the leafs. While these leafs tend to flex well and ride decent they leave a lot to be desired. Hence why you see others swamping away from them.

52" leafs- Another 1/2 ton leaf setup. From what I have read and talked with Andy about these leafs in their stock form are great performers. However there are several different sets of these leaves out there. There are 4, 5, and 6 packs out there. I believe Andy started with a 4 and they were way too soft. The 5 pack is what I have and from what i hear is a good mixture of support for on/off road capabilities. They tend to ride well on the street (when paired with a quality shock) and flex even better off-road. If you spend any time on a K-5 forum :whiteflag you will see that most of them are running their stock rear leafs (52") in the front and a set of 56" in their rear. There is a 54" out there but I haven't done a whole lot of reading on those yet. Also I believe Andy has gone to a K-20 leaf with a few modifications of his own and actually likes it better. It's a little stiffer on the road yet still provides great movement off-road.

78-79 F-150 FRONT leafs- Tim (redwagon) ran these on his bronco for a long time. From what I gathered from him he liked them a lot. However in my neck of the woods they are hard to come by. It seems like they were like the F-350 leafs in a way in that they were mostly flat so you didn't get as much side to side play out of your axle.

That’s all I know on leafs. It may not be a lot but hopefully that will help you guys a little bit. When I do my sas I plan on running a hi-bred set of 52"'s as my bronco is still driven on the street a lot. However I don’t want my off-road abilities to be hindered either. Leafs are neat in that if you don’t like how they are set up just go down to the junkyard mix and match till you get the desired ride and flex and then wheel the crap out if. They are cheap to replace and easy to find.

Just my $.02
 

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Discussion Starter #8
Great info patrick, very helpful. I will now reveal how I got into this spring question. Even though I live in the frozen northeast where heavy 4x4's are in abundance, Its rare to find f350 in the junkyards.
When I started my very slow build (2 years ago :duh) I called around, one guy said he had the f350 springs I needed. I tried them when I started fabbing up the front, they turned out to be f250 springs from the 70's. Called another guy, I got springs from him, put them in, and the project kinda slowed down since then.
All along, every time I would look at the front while it was sitting at my buddy's shop I would swear "those really look like negative arch". Finally started running the bronco last week, definitely f250 ttb springs :doh0715:.
Of course its been said over & over by guys like andy351 & rep, those ttb springs are almost double the rate (I can tell, I've never driven a 1 ton that rode that bad.) Picked up springs yesterday at the pull a part, came from a 94 350 diesel, just have to put the springs in & recheck my castor. Just kinda wondering if I should hold off & wait to find a set of springs from a 460 or 351 gasser for a softer rate
Also figuring in, on my bronco I have a quite heavy front bumper with a ramsey 10000re mounted

Overall question, go ahead & put the diesel springs in, or find some f350 springs with the lighter rate

dont have any pics to post right now, I'm on a 24 at the firehouse but heres the link to my incomplete build thread
http://www.fullsizebronco.com/forum/showthread.php?t=136717
 

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I pulled my stock 460 F350 springs out from the front of C350, and went with a leveling pack for a 2002 Super Duty PSD..

And according to my spring guru, this is the more desirable era of pack, as the leaves are thinner.... after 6k miles of eating my kidneys through parking lots, let alone trying to wheel the thing, well, I went once,,, it hops like a rabbit on Meth.

I have been chewing with how and what to do...

I have a 4 spring F150 rear pack, minus the eyes;

I have a IDI TTB truck in the back yard, with a 4 or 6" lift, drop pittman arm, TTB drop backets, Rancho's, complete set up.

One solution was to cut leaves (tune?) on the PSD SD pack, as they are all equal length.

Another was to ditch the bottom two of the PSD SD pack, and replace with the 4 pack of rear F 150's...

Another was to run the IDI lift under my 460.

Another was to "tune" the IDI pack with the F 150 leaves, swapping 3 or so of the IDI TTB (I swear its like a 7 leaf pack, nicely staggered too... )leaves out for the 4 F 150 rears, bearing in mind the eyes have been torched off the rear pack, they are simply leaves now.

I modded the front spring hangers to accept the 56.5" long SD leaves, and I am going to un modify them to accept the 52" leaves from the TTB IDI...

Maybe a redneck variant on the SKY kit down the road, but right now I just want some ride back, and okay flex..

Flexed out to basically the max right now, I had 14" difference in front tire levels, and 7" in the rear, in the pics I am going to post, I may have been able to go more, but had I flopped it off the tree, 1: its my D.D.; 2: 7th (bordering street) is busy enuff that would have been epic fail.



 

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ate lug
88 + 96 broncos, 96 F250
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Overall question, go ahead & put the diesel springs in, or find some f350 springs with the lighter rate.
I have the one-ton PSD leafs under my SASed F250 shackle-reversal style, and i like the ride, but i think it will be too stiff for a 351. The 7.3 is a shitload heavier than a 351, and these, i think, are a good pair for my one-ton 4" Skyjackers out back, ie some-what stiff. Ive had it offroad but with dual sway bars its hard to say how much theyll flex, altho it doesnt seem like much. Me personally, i wouldnt use em on a bronco.

Clydesdale is on to something; alot of guys have been putting Superduty springs in front of their 80-97 diesels because they are longer and ride a lot better. So thats another option for ya.
 

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But mine don't ride better.... Maybe if I was IDI/PSD they would, but they are STIFF!!!!!!! and bounce like a springboard...

My post was really looking for advice....

tune the PSD superduty springs?

Hybrid pack with F150 rear leaves, and SD PSD main leaf?

IDI TTB Lift springs?

IDI TTB Lift springs tuned/hybrided with F 150 rear leaves...?

I desire to float like a Cadillac, and sting like a Beamer...
 

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Clyde, I would be careful mixing superduty leafs with other 1/2 ton leafs. Most 1/2 ton leafs have a lot more arch then the SD ones do. You may end up breaking both sets due to lack of support. Andy would be able to fill you in on more of that. Also didn't you say that you have a shackle reversal kit on it? What shocks are you running?

Also the way the leafs are set up greatly effects how they will ride. I am sure you probably know this but your shackle angle needs to be at about a 45* angle away from the axle. That shackle angle is key to how that leaf will react once you hit a bump in the road.
 

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I ultimately didn't mix, I ran the IDI TTB lift ala carte (still in the middle of the swap) and gained 3" or so of lift over the Super duty leveling kit..

I haphazardly threw the SD springs under the IDI, and I measured 10" wheelwell lip to tire on the lift side, and a skoshe under 7" on the SD side, now that both sides are SD (on the IDI), I think that number has dropped to 6.5 or so, looks lower than it did.

THe top of the u bolt plate on the lifted truck, was boxed and had a raised mounting position for shocks, ironically, my factory C350 shocks are longer than the Ranchos, the Ranchos were shot anyway, compressed them with one hand, and was a mother extending.

Hedging my bets, I went ahead and lowered my shock towers, so the top bolt is int he bottom bolt position, I will either rte drill the top bolt, or weld them to the frame to provide the supporrt the missing top bolt used to provide.

The bonus to the increased lift is two fold, one this trucks next step is 40" tires, two, currently my Superduty wheels (swapped out 8x6.5 60 for a Superduty 60)have 33's, my rear tires are still 37.. was bothered by the idea of a raked truck.. aint gonna be raked for sure now...! Although, I may actually get a negative rake, higher int he front, with the 33's in front, and the 37's in the rear.

I trimmed some leaves on the TTB pack, just cause...
 

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And I just discovered that the perch width is wider on a S-duty axle, than an OBS axle.. Grrr... Guess I am calling a mobile welding place tomorrow... guy here said he charges $15 an hour... I would think consumables are half that.
 

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So, I have two hunks of 3/8th flat plate I m going to weld together to make my new spring perch, going to weld on top of the existing perch.

Since I am buying U bolts at this point anyway, and not driving the damned truck tonight, what the hell, I think, lets add to this and put a 2" tall chunk of 1/4 wall c channel under neath the plate, weld that to the existing perch, then my 3/8th plate to the top, giving myself 2.75" lift.

The C channel started out as 4" square tube, I lobbed off a 4" long section, so my mating surface is 4x4", and then halved it, so its sides are 2", and it forms a C.

If I cut tabs and fully box it, and possibly give it a support tab down the middle for a spine, how horrid of an idea is this?

This is a subtle hijack I guess, but since it started with my spring rate questions... Mods PM and I will start a different thread and then it can be moved if need be.

Basically a lift block under the springs, but welded essentially to the tube.

So instead of a 1/2" tall purch, I have a 3" tall perch of 1/4 wall tube, topped with 3/4" of solid plate (3/8 twice)
 

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So, I have two hunks of 3/8th flat plate I m going to weld together to make my new spring perch, going to weld on top of the existing perch.

Since I am buying U bolts at this point anyway, and not driving the damned truck tonight, what the hell, I think, lets add to this and put a 2" tall chunk of 1/4 wall c channel under neath the plate, weld that to the existing perch, then my 3/8th plate to the top, giving myself 2.75" lift.

The C channel started out as 4" square tube, I lobbed off a 4" long section, so my mating surface is 4x4", and then halved it, so its sides are 2", and it forms a C.

If I cut tabs and fully box it, and possibly give it a support tab down the middle for a spine, how horrid of an idea is this?

This is a subtle hijack I guess, but since it started with my spring rate questions... Mods PM and I will start a different thread and then it can be moved if need be.

Basically a lift block under the springs, but welded essentially to the tube.

So instead of a 1/2" tall purch, I have a 3" tall perch of 1/4 wall tube, topped with 3/4" of solid plate (3/8 twice)
Not a terribly bad idea, but you will get some axle wrap. If that doesn't bother you then go for it, just make sure the welds are good.
 

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i've never been able to confirm if the gassers or diesels used different springs in the 80s-early 90s. as far as i know the only real difference was presumably the front GAWR, since i think there was one or two options (and presumably all diesels came with a heavier GAWR than a small block). i know F250s had at least 2 different GAWRs and presumably 2 different spring choices, but i don't know much about F350s except they came with dana 60s and rode like shit.

do yourself a favor and just go with the 52" chevy springs. right now i've got some 4" lift springs from a blazer that work the best out of the 4 sets of springs i've run in the front of my rig. just get a pack with more than 4 leaves and you should be fine. they are really easy to tune by adding/subtracting leaves. i was able to literally bolt them in when i made the swap from f350 springs.

57" springs are nice, but they sway more and the departure angle sucks because they are 5" longer on the backside of your tire. you will hit them a lot if you rock crawl.
 

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but you will get some axle wrap. If that doesn't bother you then go for it, just make sure the welds are good.
Explain axle wrap.

do yourself a favor and just go with the 52" chevy springs. right now i've got some 4" lift springs from a blazer that work the best out of the 4 sets of springs i've run in the front of my rig. just get a pack with more than 4 leaves and you should be fine. they are really easy to tune by adding/subtracting leaves. i was able to literally bolt them in when i made the swap from f350 springs.
I thought Chevy ran a narrower spring... and will the weight difference between my 460 and a 350 matter? Presuming 1/2 ton lift is what I want to look at, and seemingly option a rat motor in a half ton was as rare as hens teeth.

I am head down the Chevy spring route, if I end up loathing these TTB springs.
 

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Explain axle wrap.


Ok, when you hit the gas your drive shaft turns the pinion in the axle, the pinion turns the ring gear with downward force (upward force in front axle), which of course in turn rotates your tires forward. Some of that energy will also cause the axle itself to rotate forward little by twisting on the leaf springs. The rear of the axle will pull up a bit and the front of the axle will force down, thus "wrapping" the springs around the axle. Obviously it doesn't actually wrap them around the axle, but he front portion of the springs will twist downward and the rear portion will twist upward. This results in wasted energy and reduced traction because the energy is used up in the springs, not getting to the tires/pavement.

When you put in a block you are increasing the distance from the spring pack to the axle tube, which gives the axle more leverage to cause more "wrap".

Correct me if I'm wrong but I believe you are doing this to your front axle?

The amount of wrap could be negligible, with only 2.75" increased distance via your welded perch/block. Also I don't know your intended uses for your truck. Mud running and street driving it shouldn't be too bad. However you may notice some increased swaying of the front end while driving and turning.

Hope that helps.
 
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