the 78 has a 4ish inch home made lift, and the 85 has a 4'' suspension and 3'' body.

 

Do a user search in this section for 'super duty 75F350' and got to the third (oldest) page of threads and work your way through. More info then you'll ever need.
Ed's (75F350) the original guy talking about it on here, and the one who helped me install his old 4" springs on my 79. It was a bolt in swap, but I can't remember the difference in the bump-side trucks and what it took to make them work.

 

And that would be me

 

ed's a bum, where's he been?

as far as i know you just have to drill out the bolt holes on the spring mount becuase the s/d springs use a bigger metric bolt, and i believe you have to hit the bushings with a flapper wheel to shave them down a little and then they fit. on the 80 and up trucks you have to move the front spring mount forward 5''s.

 

No clue, lost his number a few phones back and he hasn't answered any emails in a long while. Last I really spoke to or saw him besides on here was selling him the front end off of my 79 when I put the 73 cab on the truck. He'll turn back up if he wants to.

I think you need to drill the holes on the pre 77.5 trucks, because mine just bolted right into my 79 hangers (if I remember correctly), and the earlier trucks shackle was shorter, so they couldn't be used. Something along those lines.
Glad to hear some folks have put these in the 80s trucks, want to get rid of the stock setup in my current truck when I have a place and the time to work on it, and would much rather go with the SD springs again to get that good ride.

 

i'll search through some threads on the swap. did you do both front and rear leaf spring swaps? any chance you know what lengths the springs are and how wide? if i remember isnt 73-77.5 years 2.25'' rear leafs and 77.5-79 they switched to 3'' wide leafs?

 

SD springs are only for the front, you're on your own for the rears.
Mine was an add-a-leaf and a hi-boy stock block with stock 79 springs. Many just do a stock style shackle flip with the block, or get a set of the front hangers for the rear spring and do a shackle flip with those. The latter gets rid of the block all together (that was what I planned to do, but sold the truck with the spare hangers sitting in the bed...)
I know Ed moved his hangers around and used a set of the long chebby 3500 leaf packs with a shackle flip. He bragged about the smooth ride and still towed home new trucks on his trailer with that setup.

 

ive searched and only found alittle bit of info on doing the SD leaf swap from 75f350 he seems like a great guy and does excellent work. the setup you mentioned above sounds like what i'm after a great riding truck that will be able to still tow a trailer with a car/truck on it. i think i got alittle bit farther on selecting my lift i want atleast a 6'' to 8'' all suspension lift no blocks at all. what do you think will get me this many inches? 6'' or 8'' front SD leafs and possibly front rear leaf custom lenght shackles so they don't bang against the frame? and rear 4''-6'' chevy or deaver springs with a shackle flip? any help selecting my lift would be great

 

The 4" springs got me about 5" of lift (a couple inches over a stock hi-boy, nowadays) over the stock 79 negative arch springs with the stock lo-boy front shackle.
Even worn early springs are going to be close already to a 3" lift as far as the lift measurements on new springs go. This is my old truck with SD springs next to my stock height 63 4x4

The tires throw it off a bit, but you can see where the hubs are in comparison to each other.

If I'd got around to doing the shackle flip with the drop hangers from my 73 CS parts vehicle, it would've come out perfectly with no blocks.

If you add the stock chebby or aftermarket lift springs to that, you can get it to where you want it. As far as rear spring width and hangers, that will all depend on what springs you decide for the rear, good chance you'll be drilling some holes in the frame regardless.

With the divorced T-Case, you shouldn't have to worry about driveshaft lengths, I think Ed's red truck was running the stock length shafts even with 10" SD lift springs up front.

 

So your saying basically stock high boy leafs are equal to about a 3" lift in todays world so I would need at the lowest a 6" SD leaf spring to get my desired height? Are they 78-79 rear leaf hangers in the second picture? I got some rear 4 bolt hangers from a 79 f250 4x4 that use 3" wide leafs I was going to use for whatever leaf setup I go with I love your 63 is it a f100 or 250 I have a 64 f100 4x4 I will get working on after I'm done with this crew cab hope to start on the 64 by the end of summer my holdup now is finding a zf5 trans for the 460 that's going in the crew want one with the parking brake on back of transmission

 

A set of 6" SD springs should sit approx 4" over what you have now. The SD springs sit a bit taller in these trucks, and you'll need to add a taller shackle, since the early ones end up being a little short.
Second pic is the stock hangers that are bolted to the front of your rear leafs (77.5+ with the 3" wide leafs, or 73+ Camper Specials). If you pick up a set at the JY, you use them in the rear to replace the stock hanger when you do a shackle flip. This will drop your shackles quite a bit further down than just flipping the stock rear hanger. To mount them you do need to get the shackle angle correct and drill new mounting holes.

My 63 is supposed to be an F100, but some PO installed 70s F250 hi-boy axles under it.

 

When using the SD leafs in front the they will actually lift it alittle more then what they say they will? in other words a 6" SD lift will actually raise the front end alittle more then 6" when put on our old trucks? also when you add longer shackles to the rear of the SD leafs to correct the short issues with the stock ones will this add extra lift height to? using the rear 3" hangers for the 78-79 would it be better to use them on the front and rear of the leafs or just on the back of the leaf?

 

The 4" lift SD leafs I used sat an inch taller than a 4" leaf built for these trucks. It will vary from truck to truck and with the leaf pack used, but haven't heard any different. My friend said the same when he installed his.
With your front springs there should be a solid mount in the front, and a shackle in the rear that bolts in through the frame. On 73-77 trucks that needs to be about an inch longer than stock, which the 77.5-79 trucks' shackles were, because of the negative arch springs. It won't really add height as much as it will give the spring room to flex before it hits the frame. I wouldn't go hog wild with the length of the shackles, or you can really mess with the driveline angle.

As far as your rear leafs: Leave the front hangers the way they are (unless you install longer springs, then you get the fun of moving them forward and drilling new holes) and the should look like this:

That is from Ed's Photobucket. You can see where the holes from the stock hanger are.
I really do wish that guy'd come back around here. He'd be able to give you far more detailed info than I can.

<B>EDIT:</B>You probably will need another set for the front of the rear leafs, if you switch to 3" wide spring packs.

 

[QUOTE=ihateminimumwage;9979267]The 4" lift SD leafs I used sat an inch taller than a 4" leaf built for these trucks. It will vary from truck to truck and with the leaf pack used, but haven't heard any different. My friend said the same when he installed his.
With your front springs there should be a solid mount in the front, and a shackle in the rear that bolts in through the frame. On 73-77 trucks that needs to be about an inch longer than stock, which the 77.5-79 trucks' shackles were, because of the negative arch springs. It won't really add height as much as it will give the spring room to flex before it hits the frame. I wouldn't go hog wild with the length of the shackles, or you can really mess with the driveline angle.
QUOTE]

i'm just about ready to buy some 8'' skyjacker SD leaf springs for the front of my 71 crew cab wanted to get some final advise from you before i do. any idea if the sd leafs will bolt into the front solid leaf mounts on the frame? ive read you need to shave the bushing some and may need to enlarge the hole for the bolt. is this all that's needed or are later model mounts better to use? i will leave the stock front rear shackles on for now just for mock up then get some custom length ones made once everythings final. also when ordering which is the best to go with leaf choices a diesel or gas and spring rate i was thinking gas wiould be the way to go but may be wrong 71 f250 crew cab with 460 and zf 5 trans

 

just to add...... i could only find one place to get the metric front s/d bolts and it was some e-bay store with horrible shipping. was gonna run me like $50 for two bolts. fastenal has them from what a buddy said, but they to want $25 a pop too. a 5/8's is too small and a 3/4 is a hair too big. the bushing insert is an 1/8'' thick or more, so i plan to just drill the inserts out to 3/4 and buy some off the shelf 3/4'' grade 8's or better when i get to putting mine in.