k2500 to k3500 leaf springs? Help

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JoeFox

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Hey guys,

Im new here and have been searching the forums for some help but cant seem to find anything.

I have a 98 gmc k2500 and am wanting to beef up the rear end to haul a bit more weight (rocks and soil etc..)

Im looking for some advice on how to upgrade the rear end to 1 ton capacity. Would an add a leaf do it? Any advice would be appreciated.

Thanks
 

Supercharged111

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The 3500 leaf pack, in most instances, added a single upper overload spring. It does way more than a leaf added to the main pack. Do you have a 6 lug or 8? If 8, you can bolt the bits to the frame that engage said upper overload.
 

454cid

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The 3500 leaf pack, in most instances, added a single upper overload spring. It does way more than a leaf added to the main pack. Do you have a 6 lug or 8? If 8, you can bolt the bits to the frame that engage said upper overload.

I think that upper overload was a dually thing. I don't have that on my SRW 1-ton. I just have the superthick lower leaf.
 

Supercharged111

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I think that upper overload was a dually thing. I don't have that on my SRW 1-ton. I just have the superthick lower leaf.

Was the lower leaf thicker on the 3500? I know in a past discussion there were SRW trucks with the upper, maybe it was an option? Because I know there are people like you who don't have it as well.
 

454cid

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Was the lower leaf thicker on the 3500? I know in a past discussion there were SRW trucks with the upper, maybe it was an option? Because I know there are people like you who don't have it as well.

That lower leaf is short, and looks like it's probably greater than an inch thick at the axle tube. I don't know how that compares to other trucks as I don't really have a good point of reference.
 

Aparke4

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I can take a picture of my k2500 as I have the short thick overload spring on my leaf pack, 1996 k2500 with 454 and 14 bolt axle.

OP- have you looked into installing airbags? Most k2500's if 8 lug have essentially the same springs front and rear. My torsion bars are only one code level below the highest rating and my rear leaf back has as many leafs as other one tons I have compared against. Adding the airbags, I went with the firestone kit which adds lots of versatility for hauling and towing. I simply used the valves that came with the kit and use a small bike pump with a gauge. Simple, minimal wiring and the kit fit great.
 

stutaeng

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That lower leaf is short, and looks like it's probably greater than an inch thick at the axle tube. I don't know how that compares to other trucks as I don't really have a good point of reference.

Yeah, my 3500 SRW seems this way. I created a thread about upgrading to a DRW that has the overload. IIRC, I needed the upper overload spring, longer Ubolts and the little brackets that go on the frame for the overload. At least on mine (CCLB SRW), the holes on the frames for the brackets are already there. I saw another CCSB here that looked like it also had those same holes...

I think the 3500 SRW and 2500 may be the same 6 pack leaf, but not certain on that.

Last week I went to pick up a load of decorative "egg rock" for some planters my wife had me redo. The guy was supposed to load me 1 yard, but actually loaded me 1 1/2 yard. I don't know how much load it was, but I had about 1" between the bump stops and the axle. I've done a pallet of concrete mix before. 42 bags @ 80 lb = 3360 lbs. I think this maxes out the GVWR of 9,200 lbs, but never weighed the truck's curb weight, LOL.
 

PlayingWithTBI

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The guy was supposed to load me 1 yard, but actually loaded me 1 1/2 yard. I don't know how much load it was
Depending on some factors like size of the rock or how much sand is in road base, etc it varies but, as a rule of thumb, 1 yard weighs around 1-1/2 tons. So, you may have loaded 2-1/4 Tons or 4500Lbs.
 

stutaeng

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Depending on some factors like size of the rock or how much sand is in road base, etc it varies but, as a rule of thumb, 1 yard weighs around 1-1/2 tons. So, you may have loaded 2-1/4 Tons or 4500Lbs.

This was larger rock (about 2" round,) so I think the unit density is lower than say flex base or sand with a lot of fines. I'd say it looked like it sagged as much as the pallet of concrete, give or take. Comparison measurement was made by squinting me eye though. :banana-mario:

I did load a full yard of wet sand on my 1500 once when that's all I had. I was inside the cab and didn't see how much the rear sagged, until I got home. LOL. The 4.3 didn't seem to mind, but my braking power was reduced a significant amount. That's when I realized I needed more truck!

Here's the thread I was talking about. Some RA alternatives were listed as well:
https://www.gmt400.com/threads/k3500-srw-to-drw-leaf-springs.49155/#post-1096254

I don't know if the 3500HDs (GVWR = 15k) will swap over, I think those may be wider? I've seen those and they are massive compared to the regular pickups!
 
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PlayingWithTBI

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I don't know if the 3500HDs (GVWR = 15k) will swap over, I think those may be wider?
Could be, FWIU most of our trucks came with 2-1/2" wide springs but, some had 3" ones. Not sure when they did that, if it was with OBS trucks or NBS or maybe 3500HD? Not much help huh?:rolleyes:
 
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