Custom lift kit questions

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Joined
Sep 12, 2025
Threads
3
Messages
15
Location
Meridian, ID
I am trying to part together a 2” lift kit for my 1967 FJ40. Two main reasons I am trying to put all the parts together myself is because I really want to use Bilstein 5125 shocks and second I live right by a shop that makes really good leaf springs and cheaper then I can get in a kit.

I’m assuming all the parts I need for the kit are:
Leaf springs
Shocks
Shackles and bushings (wanting anti inversion)
U-bolts and hardware (wanting u-bolt flip kit)

These are the parts I am wanting to order. Any recommendations or suggestions are very much appreciated and thank you in advance!

I want to use anti inversion shackles but can’t get a definitive answer if these are the right size for a 2” lift. I am assuming I can’t use bigger shackles? Because I saw they did have 4” shackles but again I assumed they were for a 4” lift.


These are the Bilsteins I was going to get.


U-bolt flip kit

 
Also, I only posted the link for the rear u bolt flip kit but I do have the front kit in my cart.

I was wanting to get a steering stabilizer as well but haven’t started researching that yet if anyone would like to comment on that. Thanks.
 
You'll need pins as well, and I'd recommend buying the flip kits direct from 4plus products rather than through MAF
 
In that case can I use my OEM shackles? Or do I need bigger ones?
Higher lifts are achieved by bigger arches.
Bigger arches mean longer springs.
Longer springs equal increased potential range of motion.
Increased range of motion requires longer shackles.
 
Higher lifts are achieved by bigger arches.
Bigger arches mean longer springs.
Longer springs equal increased potential range of motion.
Increased range of motion requires longer shackles.
Thank you. That’s what I figured. I’m just not sure if the anti inversion shackles I linked in the original post are the correct size. Or could you recommend some anti inversion shackles for a 2” lift leaf springs?
 
As @brian noted, you shouldn't have to have anti inversion shackles. I've been wheeling cruisers for 40 years now, done the Rubicon over a dozen times, and none of my rigs have anti inversion shackles.

And all of my rigs have extended shackles.

Hint: if you're having springs made, just tell them to make them 1" longer than 'normal' because most of the lift springs that are on the market are too short, which is why anti inversion shackles became necessary in the first place.
IMG_5282.webp

If you look at the shackle in the background, that is what you typically see with replacement springs. If you look at the one in the foreground, that is what it looks like with a spring that is 1" longer/further forward.
 
Last edited:
As @brian noted, you shouldn't have to have anti inversion shackles. I've been wheeling cruisers for 40 years now, done the Rubicon over a dozen times, and none of my rigs have anti inversion shackles.

And all of my rigs have extended shackles.

Hint: if you're having springs made, just tell them to make them 1" longer than 'normal' because most of the lift springs that are on the market are too short, which is why anti inversion shackles became necessary in the first place.
View attachment 3991942
If you look at the shackle in the background, that is what you typically see with replacement springs. If you look at the one in the foreground, that is what it looks like with a spring that is 1" longer/further forward.
Great thanks again for the info. I’ll look for a set of shackles for a 2” lift and not worry about anti inversion.
 
The shackles in my photo are made and sold by me.😊 I happen to think they are superior shackles because they are adjustable width. And anyone who has dealt with more than one Landcruiser suspension knows that spring width and bushing shoulder width vary, making fixed gusset shackles problematic.
 
The shackles in my photo are made and sold by me.😊 I happen to think they are superior shackles because they are adjustable width. And anyone who has dealt with more than one Landcruiser suspension knows that spring width and bushing shoulder width vary, making fixed gusset shackles problematic.
Oh awesome. If I could buy a set from you that would be great!?
 
As @brian noted, you shouldn't have to have anti inversion shackles. I've been wheeling cruisers for 40 years now, done the Rubicon over a dozen times, and none of my rigs have anti inversion shackles.

And all of my rigs have extended shackles.

Hint: if you're having springs made, just tell them to make them 1" longer than 'normal' because most of the lift springs that are on the market are too short, which is why anti inversion shackles became necessary in the first place.
View attachment 3991942
If you look at the shackle in the background, that is what you typically see with replacement springs. If you look at the one in the foreground, that is what it looks like with a spring that is 1" longer/further forward.
Mark- can you explain the science behind why the one in the foreground will contribute to better manners/handling?
 
I am trying to part together a 2” lift kit for my 1967 FJ40. Two main reasons I am trying to put all the parts together myself is because I really want to use Bilstein 5125 shocks and second I live right by a shop that makes really good leaf springs and cheaper then I can get in a kit.

I’m assuming all the parts I need for the kit are:
Leaf springs
Shocks
Shackles and bushings (wanting anti inversion)
U-bolts and hardware (wanting u-bolt flip kit)

These are the parts I am wanting to order. Any recommendations or suggestions are very much appreciated and thank you in advance!

I want to use anti inversion shackles but can’t get a definitive answer if these are the right size for a 2” lift. I am assuming I can’t use bigger shackles? Because I saw they did have 4” shackles but again I assumed they were for a 4” lift.


These are the Bilsteins I was going to get.


U-bolt flip kit

I ordered my springs from Alcan springs in Grand Junction, CO. They will reach out and discuss what you are trying to achieve and ask about loading on each axle. I had them make me a set with a 4 inch lift.
 
Mark- can you explain the science behind why the one in the foreground will contribute to better manners/handling?
Jesse (and all), try this simple test. Put your feet about 16" apart (maybe more if your balance requires), lock your knees, and do a little hop. Just a couple of inches, nothing big. You will feel the jolt transfer straight through to your neck.

Now bend your knees just a little and repeat. Chances are good that the jolt won't get past your hips.

In the INITIAL moment of impact, when your truck hits a bump, BEFORE the spring has a chance to stretch, BEFORE a vertical shackle has a chance to rotate, the initial shock tranfer rate to the frame is high. If the shackle is already bent, your suspension is primed, compliant, ready to move, ready to accommodate.😊

IMG_2449.webp

Some might consider my shackle angle on the Karma Cruiser excessive. I can tell you that it rides like a dream, flexes REALLY good off road. And it will likely never have to worry about inversion.😉

I wrote a tech article about this over 15 years ago that I was going to submit to the Toyota Trails for publication called The Angle of the Dangle. But owing to the horrible treatment I received from them after donating an FJ40 for a raffle truck, I never submitted the article.☹️

If you find this information useful, consider hitting the like button.😉
 
Last edited:
Oh awesome. If I could buy a set from you that would be great!?
My contact info is in my avatar and my signature line. If you can't see it for some reason, try rotating your device 90 degrees.
 
I posted a photo of mine when I was checking to see if my frame would flex and cause the bolt on my steering u-joint would make contact with my water pump neck and the shack was getting close to the frame at the point that I stopped raising the DS of the axle doing the check. I was told my shackle was too short. This is all the flex I would want.

1757942786542.webp


Now I am not going to worry about it and just make sure my bump stops keep me from making contact with my TREs and the shackles to make contact.
 
Having run perfectly vertical shackles (harsh!) on several “kits” myself over the years @65swb45 is of course correct. In particular I would do this hint..

“Hint: if you're having springs made, just tell them to make them 1" longer than 'normal' because most of the lift springs that are on the market are too short, which is why anti inversion shackles became necessary in the first place.”
 
You can buy a kit and not buy the shocks. I run the procomp springs (discontinued now) on my 40 with the bilsteins. I run OME with bilsteins on my 60. Sometimes, cheaper may not be better. Redline Cruisers has a new kit out that is getting good reviews, they may sell the kit minus the shocks?

What I’d worry about with a shop making a spring is getting way too stiff or way too soft of a spring. They might be good at making springs but if you don’t know exactly what you want they’ll make what they think you’ll want, which could suck. A lot of people also aren’t honest with themselves how they really use their vehicles so they spec out a part that will benefit them 5% of the time but be terrible the other 95%.
 

Users who are viewing this thread

Back
Top Bottom