I thought I read on here that a stock SD front spring will provide around 4" of lift on an otherwise stock 78-79 3/4 ton. I was doing a search and couldn't find that info again. I did see where people were ordering new 6 or 8" SD spring sets and getting a couple inches higher than that..which makes me wonder if I got my info confused. Maybe I need a 2" or 3" SD spring to get 4" lift on a 79?

Bottom line: looking for 4" susp lift for my 79 with as good as ride quality as possible...this truck is not wheeled. I also hear the late model bilsteins off the SD's provide a nice ride too....i need to do some more research on where to locate those.

 

Since we have been discussing this topic, the idea or concept of using stock SD springs has become a bit of a mystery. I believe that I recall someone aslking about the use of them and the reaponse was that the stock SD spring has little to no arch to it and will not provide much lift over stock 79 Front springs.
SOme of the advantages of the SD spring is a longer length and this improves the shackle angle, thus creating a better ride and adding some articulation.
IN order to answer this question, one has to know which SD front spring to use. There were several stock aprings available and all of them would offer a different ride heigth.
Personally I would not be quick to jump into a set of stock springs to swap but cant really answer how much a set of leveling kit replacement leafs would lift a stock 78/9 truck. I have a gut feeling that a 3" leveling kit that used replacement front springs would be ideal for this application, but have not found anyone that is willing to spend the money to try it. I mean these are cheap enough and they would be worth a shot. I would not be afraid of doing this, but I probably would not be quick to use a stock V code or better stock spring.
Now, about a year ago, I did suggest that a stock V code or better spring be used in conjunction with the then Donahoe racings mini spring pack. I do believe that this would be a pretty ideal situation, and would offer the desired ride heigth.
Part of the reason why this is such a mystery is because the SD front spring install is a lift alternative for trucks greater than 6 inches. See the aftermarket does not support this much lift and we have had to find alternatives to custom lifts, and the SD front leaf springs in the 6, 8 and 10 inch veriety works well.
There are several kits out there that make a 4" front spring that works fiarly well, and most guys looking to lift their vehicles this much simply buy an off the shelf lift kit.

Stock Highboy leafs are interchangable, and will provide this amount lift.
We did install some 4 inchers (SD aftermarket leafs) under a 79 truck a while back but it netted over 4 inches of lift.

You will have to measure the springs while they are on the ground. Measure accross the sprng eyes to achieve a straigh line, then create a straight line at the bottom, and measure the distacne between the lines. Compare the two and calculate the difference. this difference will be the amount of lift you will achieve.

 

Thanks for the post man.

The only thing I see with that measurement is if the springs have a different spring rate. Still, it would probably be "close enough" to the lift Im' looking for.


The most important thing to me is the ride quality. I hate oversprung trucks. I read (in fact it was your posts I'm sure) that the SD leafs provide the best ride quality so I'm unsure about buying an aftermarket 4" spring made specifically for a 78/9. I may still be disappointed.

Anyone ever try the superlift softride springs? how's the ride quality on those?

 

You are correct about the rate, but with this method, it will get you close enough to find the correct or desired ride heigth.
I understand the concern regarding dissapointment when a new spring is purchased, but the same level of dissapointment is present when experimenting. Heak, you dont know how nervous I was when I tried my first set of 8 inch SD springs. It has still taken some work to actually get them to work well. I am pleased with the results but may have the same concerns with a smaller lift using unkown springs.
Fear of the unknown is always a concern, and I wish we could find someone to actually try some of these options.
I have even offered to perform the labor for free if someone were to bring a 78/9 truck to my shop. I am that interested, that I would install some springs under one, if I could find someone in this same situation.
Maybe if I buy another parts donor truck I can find out.
Perhaps if you were to attempt this, you could keep us all posted.

Ths SD springs aork well for many reasons.
They would include:
Longer length:
As mentioned before, the longer length (54 inches VS 53 inches stock) correct the poor factory shackle angle found in our trucks. This added length also provide a little better flex, but the shackle angle is better wiht the proper angle.
Narrow frame:
Since the frame on our early trucks is about 5 inches narrower than the later SD trucks, the springs are closer together to each other and this will kill or take away some rate during compression cycles, promoting better forced articulation.
Better rates:
Better steel and better more progressive rates found on the later model trucks will add to the better ride characteristics not found in out older trucks. Remember that the springs under our trucks are 30 years old, and they do not have too many leafs. Long ago spring technology was limited and springs were thick, and lacked the ability to bend / flex.
Aftermarket support:
Late model trucks have the very best of aftermarket suport, and will use the latest design techniques to help build springs.
There are several other small reasons why the SD springs have an advantage, but these are the key things.

Again there is the unkown factor with trial and error. Just gonna have to find someone to take the plunge with this one.
I have a buddy that might be needing some new springs, and the Deaver type spring might find its way under his, but he has a Cummins in his, and this would change things quite a bit.
Lets see which direction you end up going. Should be fun.........

 

Hey all, I plan on putting a set of stock superduty diesel springs in my truck (79 f250) I got the springs for $50 and are basically new because the ownerput a lift on his truck right after he bought it new. My stock springs are shot and are arched negatively and leave me with about 2" of down travel!! Hopefully these will help a little and also net some more lift because of the heavy weight of the diesel vs. gas motor....let you know in about 2 weeks.

 

please do post up your findings. I'd be interested to see what these stock springs do to ride height.

 

has anyone found anything more out about this topic? I too have a '79 F-250 that I want to lift and replace the springs inexpensively. I heard there was a website that you could look up your vehicle and enter the lift you want, then it tells you what springs off of what vehicle to use to do it! Sounds pretty cool, I'm still trying to find it. The guy I got the truck from said he put 1 ton springs on the truck...who knows for sure. He is an idiot. So I do know I want to replace all 4 spring sets.

 

Much has to do with the amount of lift that you desire. There are kits available and reasonable lifts are an option.

Here is a link for some results.
Think I would still like to try this myself to see if perhaps with some tinkering the results might vary.
Anyway:

https://www.ford-trucks.com/forums/8...-bad-help.html

 

I was the one who tried it in that post. With some longer shackles, this swap would most definetly work. I just stumbled upon a cheap set of lift springs, so instead of fooling around with shackle lengths, I opted to go the easy way out. I may come back to this some day, but I will make some drop hangers and shackles to accomodate. To put a stock set on, you need to grind the superduty bushings down, drill out the the hanger, and make a longer set of shackles (how long I don't know, but at least 3" longer I would guess maybe more).

 

With the spring only being an inch longer i dont see why you would need 3" or more... but then again im not a suspension guru. Atm im in the process of building 2" shackle lift and maybe 2.5" shackle lift. Gunna run an add a leaf with that to keep the truck level and from over-taxing the springs with the diesel in there. That is until i can do the SD spring swap in the front and Chev 3/4 ton springs, shackles and hanger in the back. Once the truck is leveled im looking for about 2-3" more lift, so i may very well try the stock SD spring first if i can get a deal on em. I cant see that a SD spring wont net any lift over ours, considering the differences in weight.