Highboy lift kits
 

Anybody know where to get big lift springs for a 75 F250? I mean, 'big'. Like 10" lift approx. Should I just talk to the spring shop?

Cage Off-road was supposed to be in the development stage of the hiboy lifts for mass production, but I haven't seen anything yet. They were supposedly trying to make lift kits that were more than the standard 2 and 4" kits that you buy from like Skyjacker and Superlift. As a matter of fact, I learned this from a thread on here some time back. I checked their site yesterday and they still don't have anything for our trucks. I guess I could call them next week and see what the status is. That would be cool though to get a 10" bolt on kit!

eaton springs will custom make springs or if you got a local spring shop i would say use em.

Search for SuperDuty lift. That seems to be a decent alternative. I assume 75F350 will post in here soon, as he has done it, or you can PM him.

So are the superduties built with narrow springs that bolt on to are trucks or do you have to replace the spring perches and shackles?????????????????????????

We have always discussed the use of SD front springs as an "alternative" for 73-79
F-250's, and while these are just that, alternatives, they are not a complete bolt in kit, like most would prefer.
The SD spring can only be used in the front, and if used under a 73 to 77 truck, will require some modification. The 77.5 to 79 truck requires a little less because of the longer hangers and shackles.
Custome springs are always a better "bolt in" option, but this option carries with it a small price. Alright, sometimes not a small price, it is a rather large price.
The SD spring is a very cost effective solution for guys wanting to lift more than 6 inches, or can find the justification to make them work. They do ride and flex rather well, but for only 4 inches to 6 inches of lift, the store bought kits can be a reasonable value.
For those that need a little extra lift, and performance, and not afraid to get a little dirty with some fabrication and modification, the SD spring offers a decent solution.This can be accomplished for a little bit of coin, but does require some work.
Kits are great for convenience, and for some, the kit is a great way to go. This is why they are so popular.

Understood, I just was needing some tall springs for my highboy. Looks like I should talk to the spring shop. Thanks.

How tall is tall?
8" SD springs will clear 42's without much of a problem, and can be bought brand new for around 500 bucks.

I am lookin to go about 10". Give or take. I have a local spring shop, they were extremely reasonable when I had u bolts made ($9 a piece after tax)

ok so spring shop said $350-$425 for lift springs, how hard is it to make the super duty springs work? Where is the work? I have 2 1/2 leafs on the the rear, I assume these will have to be custom regardless cause everything after highboys had 3" rears I believe....correct?

Ah haaaaa, now we are starting to see why alternative lifts are becoming popular.
With 10 inches, one could assume that you have a desire to clear 44" rubber right?
I only ask because, 10" SD front springs will give you greater than 10 inches of lift over your stock heigth.
I am assuming you are lifting "mean green".
You will have to grind the spring eye bushings a little to fit inside of the 75 spring hangers. A few minutes with a flap wheel, and an angle grinder will make short work of this.
You will also have to make longer shackles for the front springs. If you do not jump the truck, or get overly aggressive, you can get away with ashackle that is 5.25 inches. This will clear the frame, and allow a decent amount of pivot. The shackle angle will increase with the use of the longer SD spring, but this angle is good, and contributes to the better ride quality.
At this time, you will probably want to replace the front pivot bushings. I can guarantee that your 30 year old ones are shot.
You will want to be aware that this extended shackle does affect "caster" so caution must be used when making this modification. Too long, and the pinion angle gets whacky, and the truck steers very slow.
You will have to remove the entire leaf that makes up the "military wrap". This is the second leaf in the pack. The diameter will not fit in the stock hanger. I have run with the entire leaf removed, and have cut the wrapped portion out of the pack. Removing the leaf itself allows for more flex. I have yet to encounter a failure, or bend a main leaf after a removal. I am pretty hard on my vehicles.
After this, the spring mounting hardware will have to be addressed. The bushings are a larger diameter, and will require you to drill the hanger to a larger size. You can either drill to 18mm and buy an 18mm bolt for the front, or make the bushing larger to accomodate a 3/4" bolt. Since you are making your own shackles, you can use the stock size upper bolt, and drill the lower to the appropriate size. Easy as pie.

For the rear, you have many many options here, but the best so far, is to ditch the stock leaf all together. You will probably consider a shackle flip, and since you are removing the rear pivot, you might as well remove and replace the front one as well.
What I did was remove the front fixed hanger, and mpunted it to the rear. This creates a new mount for the shackle. For the front fixed mount, I replaced mine with a late Chebby hanger. It was longer and created more lift. These lift figures will vary depending on how you mount it to the frame. The longest hangers can create as much as 6 inches of lift when combined with a shackle flip.
Alright, so you have the hangers off completely, and now you have a few options. The best option here is to use a 64" long rear leaf, also from a late model chebby truck. 2wd, or 4wd this does not matter, and it will fit the shackle, and hanger from your highboy.
I used the very end bolt holes as a reference for my new bolt holes. The very outside holes became the inside mounting holes. This required me to drill a bunch of holes for the new 1/2" hardware, but I was confident in axle alignment because I was able to use 4 existing holes. Shackle angle is at 23 degrees, and has a bunch of flex with a 2wd 1500 64" stock leaf. Longer skackles will change this, blah, blah, blah.
You get the idea. Here is a pic. feel free to cruise around and see some of the other mods required for this complete modification.
Image of rear shackle flip with 64" sping - Photobucket - Video and Image Hosting
Weigth capacity is very limited if you use a 1/2 ton rated spring. The fix here is to use a 3/4 ton spring.
Lift figures will vary based upon different springs, and which hangers you use. It is very easy to create the 10+ inches of lift with this method of lift, and though it sounds rather complex, it is really pretty easy, as long as you can read a tape measure, and are carefull to attach everything with saftey in mind.
These rather flat springs really flex well, and offer a fantastic ride over the stock units. Because they are flat, they do a pretty good job of controlling the axle, and help to eliminate wheel hop. I can really lay on the throttle, and spin up the rear tires in any condition, and the axle does not hop. It does get a little wierd if I lock the brakes up, but this has only happened once or twice.
While this combo sounds like a bunch of work, when compared to the amount of work required for a similar modification, the rewards are well worth the effort.
Shock lengths become the limiting factor, because the springs at this point are capable of more travel than the shocks can travel when using the stock mounting locations, but for the weekend user, the stock locations will be fine. For a more aggressive user, new mounts that are farther apart will be a benifit.
I am still working out the bugs for additional travel, but I am using just about all of the stroke of a 14" front shock. Not bad for such a large truck. Fenders really suffer (Thanks again to Steve / chasetruck754 for all of the fenders I keep crushing, lol), a little because of the additional flex, but this can be eliminated with the use of an aftermarket bumpstop.
Guess I should state the obvious: brake lines, steering, driveshafts will all have to be addressed.
Hope this helps out some.

Yeah that helps a lot. Even If I need to figure out rear springs it's nice to know the front springs are more readily available. That's not really as much work as I was thinking...So a longer swing shackle on the rear of the front springs and do something about the front part of the spring being a little wide.....If I read correctly that's the front in a nutshell, correct?

Yes I am trying to clear 42's, road use only. I have mud toys- this isn't one of em. I want something that turns head when I drive it to the cruise-ins, ya know what I mean? I already have 42's I just need to get em under the truck :) I used to run em on the that orange truck till they limited stock class to 40's or under and 33's or under.

I assume on the rear in that pic they swapped to 3" springs? If i do that there is a lot more availability with the low boy trucks, correct? Are the rear spring hangers the same on those trucks as my highboy? I know they make tall springs for the later 70's trucks. My rear shackles are pretty much all shot out back so I spose I could do some work there.

Now I need to get that drum front axle out of there to stop thise hore she doesn't like to stop with 33's let alone 42's. I think I will find a disc brake D44 and do a disc swap on the rear, that should stop her.

Ever think about fabbing up some drop hangers? 10" lift is gonna make some mad lookin banana leaf springs. Maybe drop hangers for 4" then use the SD 6" lift front springs?

I think I'd prefer to stick with all leaf, not concerned about ride, more about keeping it simple. Money isn't too big of an option after july(when that dang ring on her finger gets paid off LOL) So I guess we'll see where the road takes us.

Question:

Length-wise, how much difference is there from 73-79 rear springs compared to 80-96 trucks? A friend has 8" lift rears for an 80-96(so he says)