how do I mix J/Y leafs and get the same lift?

[Skyetone]

I have a 80 toy truck. stock suspention right now. The front leaves are almost neg arch by about an inch. thats about what they are stock. The rears are maybe 3 inches free arch? I really don't know without a measurement. Anyone?
I have a set of 2.5 inch yj's that I plan on outting on the front. I am planning on using NEW 2000 S-10 ZR2 rears on the rear. both have a high free arch, both are sua originally and will be soa when i am done.
I plan on using a basic lift shackle in the front, but can varry the length of the rears to help with lack of lift.
I think the fronts are going to be way high. I would like to be able to tell how much lift prior to instalation. Both front and rear. CAn I check free arch measurements and then compare and rough guess? Or will the fact that the fronts are much flatter stock screw up that idea.
Anyone got some tech input?

 

[1993yj]

I tried doing the same thing when I put XJ srpings on the rear of my YJ. I dont know how, but for some reason I measured that I was going to need 4.5" XJ springs (I measured of my bros XJ with 4.5" rear springs), but when I put them on I was about 5" too high. I ended up just having to go with some stock height springs, which sucks cause now I have a brand new set of 4.5" XJ springs laying in my garage that do me no good. Anyhow, my input would be if you have the YJ springs already, maybe the easiest thing to do will be to put them on and then measure from there as to what size springs you will need. I dont know if that helps, but that is about all I learned from using different springs. There is probably some way to figure it out before hand, but actually installing them will tell you for sure.

 

[Skyetone]

yea, but I don't need extra springs layin around LOL

 

[Skyetone]

23 views and one answer? Too techy for ya? do you think like aaa spring would know?

 

[mwmx54]

you need to take into consideration the front weighs more than the rear, which springs are stiffer i would put it together and which ever is higher, just take out springs and soften it up until its the right hight. you sould be able to hold the springs up and see... call AAA spring, they are pretty technical.

 

[TheBigSgt]

I would call Tough country and see what they think.

 

[Greg]

I doubt you'll ever be able to tell exactally how much lift you'll get out of a pair of springs NOT built for your application.

But, here's what I do know about YJ's on the front of a Toy. I ran a set of 4" YJ leaves on my old Toyota, the red one you knew. YJ's lift a Toy about 1" more than a Jeep, so your 2.5" springs will give you 3.5" lift. Now the YJ springs I ran were CRAP. They rode stiff, flexed poor and I lifted front tires everywhere. I didn't like them at all. This may have been a stiff spring set, but IMO a Toyota is much lighter than a YJ and those leaves weren't built to be on a Toyota.

With the recent buildup of my 4Runner I decided to buy springs that were built for my specific vehicle. I went with All Pro leaves & couldn't be happier. They ride killer... like, the ride of this old 4Runner is amazing, I think you'd be impressed. For the money you'd save by using cheap YJ spings, the pros of a cheap spring far outweighs the cons. Plus leaves built for your rig are built for wheelin' in mind: Center pin moved for more firewall clearance, longer spring for better ride/flex, etc.

If I were to do it again, I'd buy All Pros in a second.

Good luck with your build!

 

[Skyetone]

see greg heres the deal though. I have the ugly john holms mobille still. Stock waggies front all pro rear with a buggie. the springs have settled. in fact the front has settled too much. but thats my ugly truck.
This is a decent bodied 1st gen. I just want lift. I may put gears in it but it is being built for pavement pounding. I understand there is high arch to these spring packs. if I wanted good sprigns I'd try durangos rear. I bought the YJ's years ago here. They are practically new. I don't get how a 2.5 inch SUA lift can lift a SOA truck 3.5 inches. the s-10's would be for the rear of a truck already. when they get BDS? SOA conversion/IFS lift it's a 5" lift. but thats retaining the stock springs they already had with the free arch from the factory. now if the free arch in the s-10's is say 3 inches higher than stock toyota rears would that give more lift? Same Q for the fronts compared to stock. Yea I need to get to AAA spring and pick there brain. I am a little buisy with life right now. Hoping to get ideas here.
Frankly I need to 22r the beast first then lift the 1st gen. but thats the fun....

 

[Zombie]

What up hippy?
Your YJ leaves lift a toy differently due to the fact that the two vehicles have completely different perch locations, also the 4.0 is a boat anchor, weighing almost the same as a small block chev V8, so the springs are expecting a heavier rig.
The S10 question I might have a little more practical experience on. Those trucks are Spring under (rear) from the factory. The BDS and Superlift does a flip. The Chevy truck will weigh almost the same in the back end with nearly the same (if not less) load expectation. I would suspect the difference in the free arch between the S10 and toy springs to be very close to the lift you will see from the springs. I might also know where theres a set of used 02 leaves for free... I'll let you know.

 

[Skyetone]

if you are swapping to soa then don't you automatically cound the width of the axle as lift? then also the yj's have exactly the same eye-eye perch lenth. would position on the frame count? I am ALL ABOUT free....