1500 vs 2500 springs

[anesthes]

I have a K1500 I built. The last owner put some brand new springs in it. Fronts have like 6 leaf super HD great stiff springs with 4" lift. Truck barely goes down when the plow is on.  The rear however, have some 3 leaf super-arched 4" lift springs that are like marshmellows. If I'm walking in the bed, I might fall overboard its soo soft!

Is it safe to assume K2500 springs are stiffer than 1500 springs, so if I got some used 2500 springs and tossed a few add a leafs to get
the ride height about the same as the front, it would be ok?

-- Joe

[Blazin]

Should be fine. Normally I would say it will make the ride harsh, but you say it is already very stiff in the front so it probably already rides like a coal cart. I have built spring packs many times over the years. Some times with good results, others I went over board.

[anesthes]

Sounds good.

What do you think the used value is of two basicaly new 4" lift rear springs if I were to try to sell them?

Another question since you seem to be the pro. My crossmember has spacers in it, droping it about a 1/2" down. Do you think they did that to help with the pinion angle? The truck used to have 3" lift body blocks too. I'm having issues getting the transfer case to shift between 2H and 4H and I wonder if it's those shims. There are little triangle wedges too under the rear leafs.

Are the front + rear "add leafs" the same? I.e, can I take one of teh small leafs out of the front and stick it in the back? (removing an inch from the front, and adding it to some stock 2500 springs in the back) ?

I appreciate the response!

-- Joe

[anesthes]

I'm probably going to replace the rear springs with some 8 leafs out of an '87 suburban. Junkyard says they are 52" so they should fit. (although I thought the 8 leaf springs were 56"). I'll probably take 1-2 leafs out of the front.

-- Joe

[Captkaos]

1/2T springs are 52, 3/4T up and heavy halfs are 56".  I can't remember what the burbs were, but I was thinking they were 52...  Don't quote me on that....

[Blazin]

Probaly did the spacer to help the angle yes. although I hav e had 4' lifts in trucks with no spacers and had plenty of yoke clearance.
 Not sure on the front and rear add a leaves. I have done this several times with great results. Install two 1/2 ton rear spring leaves in between the front leaves. Gives it about 2' of lift and helps alot with plow weight. Dosn't ride bad either.

[anesthes]

Those clamp like things that hold the leafs together, if I remove 1-2 leafs out of the front, how do I re-clamp it?
I want to try and take 1-2" off the front 4". If I run the suburban 8 leafs in the back, I can add a few leafs on the bottom to get it to
about 2" so it rides even.. I figured i'd remove a leaf or two from the front, and put it under the back. No?

-- Joe

[Blazin]

With a big hammer.
 Its a guessing game when you are playing with home built spring packs.

[anesthes]

Fair enough

Perhaps I should just, remove one bottom leaf off the front (the small one) to take an inch off, run the 8 leaf rear springs with
two 3" blocks. Should make the rear more stiff and reduce ride height by an inch around.

May I ask one more question. Is it safe to assume the 3/4ton 8 leaf springs will have the same ride height as a stock 5 leaf 1/2 ton? Or do I need to measure somehow?

I'm leaf spring stupid. if you haven't noticed. But I appreciate your time.

-- Joe

[Captkaos]

The 3/4 springs are going to be taller than the 1/2 from my experience.

[anesthes]

Hrmm. I wish there was a way to measure, rather than just stick 'em in and them measure ride height.

At what point do you need wedges to correct pinion angle? 2"? 3"?

-- Joe

[VileZambonie]

I'm slightly confused as to what your goal is. You want a lift or heavier duty springs? OR Both?

I wouldn't worry too much about the pinion angle unless you are going over 4" Putting a 1" spacer on the crossmember will work up to 4"

[anesthes]

OK let me explain better.

I have a 4" lift in the front, using some very heavy duty springs. (for plowing) I didn't put them in, previous owner did - he plowed too. They are GREAT! They are 5 leafs. There is also a drop pitman arm, so the linkage is straight in the front - so I'm not gonna mess with the front.

The rear springs, are 4" lift as well, but are VERY soft trail springs. 5 leafs total, with a huge arch. But are just too soft for loads, and the rear bounces all over under bumps.

Today I bought some 8 leaf 3/4 ton suburban springs. I'd like to run them in the rear to keep it stiff back there. I think I need to add 2" blocks to them to make the ride height even. But I'm not 100% sure. 

My cross member has 1/2" spacers. Do I need them?

My rear end has unknown wedges, I'm assuming to keep the pinion angle in check to avoid ujoint destruction and vibes. How do I know they are correct?


-- Joe

[cwertman87]

yea I'm thinking of doing the same i got an 87 k1500 and i want to put 3/4 springs in because the 1/2 tons are shot! and i also want to stiffen it up a bit. i have a buddy thats got the springs i just gotta let him know if i want them and if they will work.

[anesthes]

Well, I found that the suburbans used 52" springs on the 2500 models, so thats what I used. Otherwise from searching this site, all 2500 trucks had 56" springs. (though that might not be entirely true either).

I think, the 2500 suburban springs will add about 1 1/2" to the ride height from stock. (stock should be 35" in the rear, correct?). Right now with the soft trail springs I have 39" in the rear. So I figure, with 2" blocks I'll get about 38.5" in the back, so it will be about the same height as my fronts. (Fronts are 34" stock, mine with 4" lift comes out to 38").

-- Joe