# 2500 vs 3500 OBS differences.



## 70monte (Feb 5, 2008)

Can anyone tell me what the differences are between the 88-2000 2500 and 3500 trucks? I was looking at a 98 K2500 ECSB with a 454/4L80E today. I currently own a 98 K3500 RCLB with a 454/4L80E. 

Both trucks have the 14 bolt FF rear with 6 leafs springs. Both trucks have the floor shift 4x4 except I think I read somewhere that the K3500's have the Borg Warner transfer case only. I know that mine does. I know mine has a power steering cooler but I didn't see one on the K2500.

Are the frames and front suspension and front diff the same between these two trucks? Any other differences?

The truck I was looking at today only had 86,000 miles on it and had been garaged all its life. It was very clean but had a cracked windshield and by looking at the front tires, it needs a front end alignment. The guy wanted $12,000 for it though and I'm not sure its worth that. I paid $8745 for mine back in the fall. I would prefer to have an ext cab Thanks for any info.

Wayne


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## B&B (Nov 4, 2006)

There actually isn't many differences between the 2500 and 3500 SRW trucks.

The frames have slight differences, but not much.

Front suspension components and front diff are the same. May have different T-bars but thats dependent on how the truck was originally optioned.

The 2500 _should_ have the 9.5 semi floating 14 bolt, but a few were built with the 10.5 full floater. The 3500 will definitely have the 10.5 full floater.

Like the T-bars, the rear springs are also dependent on how the truck was optioned. May or may not be different.

Engines and transmissions are the same as well. No special differences between the 2500/3500's. 3500's will usually have the PS cooler due to the hydroboost brake system the 3500's used. Most with the 454 also had the aux electric fan mounted in front of the radiator as well.

Some 3500's won't have a passenger side airbag, depending on exact year.

The main differences is simply the GVWR and the original tire load ratings.


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## 70monte (Feb 5, 2008)

B & B,
Thanks for the info. The rear diff on the K2500 that I looked at today had the same looking rear cover as my K3500 so I'm assuming they are both the 14 bolt FF. Today I was at the junkyard taking parts off of a 98 ECSB Z71 that had the F44 HD Chassis option with a 14 bolt SF rear with the six lugs. Is there any differences between this rear end and the 14 SF rear used on the 2500 trucks with eight lugs?

The rear springs looked the same but maybe the leafs are thicker on the 3500. I have not compared both side by side. My truck has the F60 HD front spring option which I guess are HD t-Bars since its a 4x4. The GVR on my truck is 9200lbs. Most 2500 trucks I've seen have a max of 8600lbs. 

Didn't the 2500 trucks come with Hydroboost? Last year I looked at a Reg Cab K2500 with the 454/4L80E that had Hydoboost but the brake fluid resevoir was smaller than the one on the K3500 truck that I ended up buying.

I have never seen a 2500 or 3500 with a passenger side airbag. They have all had a compartment on that side. 
Thanks again for all the info.

Wayne


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## B&B (Nov 4, 2006)

The SF 9.5's are the same (internally) between the 6-lug and 8-lug version. The only differences would be the brakes and the axle shafts of course. 

Should have grabbed that 6-lug 9.5...they're tough to find.

The GVWR's are fairly standardized. 8600 lbs for the 2500's, and 9200 lbs for the 3500 SRW trucks. Of course there were a couple variations in them, like for example a light duty classified 2500 that had the 6-lug 9.5 SF and/or the 4L60E trans. They were usually grossed at somewhere between 7200-7700 GVWR. There were plenty of 8600 GVWR spec'ed trucks that used the 9.5 SF in the 8-lug configuration. 

Some 2500's through the years did use the hydroboost, but the majority of them were on diesel equipped trucks. Not a lot of 2500/gas engine combo's had it. Most were vac assist.


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## calhoun (Oct 18, 2003)

The confusion, with this year truck is the 2500. There was no actual designation of HD. However, like today, there were 2 different 2500. The one you are describing has the C6P option. This is like todays HD. It has the FF rear end. The only difference between it and the SRW3500 is the size of the rear drums (The 3500 are wider), and available option and cab configurations.


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## B&B (Nov 4, 2006)

Sure can add confusion for guys that are looking to purchase these year of trucks.

C6P = 8600 GVW

But an 8600 GVWR truck can still have _either_ the 9.5 or the 10.5. Never rely on the RPO's alone if you want the bigger 10.5 rear end or drive train. They were rather year specific throughout these model years. Only way to verify 100% is to check the truck in person.


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## 70monte (Feb 5, 2008)

Guys,
thanks for the additional info. It does seem there is a lot of confusion between these trucks.

B & B,
I'm thinking of picking up the 9.5 14 bolt SF in that 1/2 ton ECSB Z71. The guy wants $650 for it. Its missing one of the brake drums but seems to be complete otherwise. The truck has about 130,000 miles on it.

I also have a 98 ECSB Z71 with the 10 bolt that I was thinking of trying to swap this rearend into. I would try to get the springs with the axle since they have one more leaf than my truck has. Will my current brake lines hook up to the 9.5 14 bolt or would I have to modify them? I assume I would have to have a different driveshaft? The junkyard truck is missing its driveshaft. Is $650 a good price for this rear? The funny thing is, he also has a 99 K3500 RCLB with the 14 bolt FF in it. A couple of weeks ago I asked him what the price was on its rear and he quoted me $450. I almost bought it since it seemed like a good price. Thanks again.

Wayne


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## B&B (Nov 4, 2006)

The fact that he wants $650 for the 6-lug 9.5, but only $450 for the 10.5 is a clear indication of their scarcity.

Swapping your current 8.5 for the 9.5 is an easy deal. Use the hard lines and flex hose already on the 9.5. E-brake cables will work as well. Drive shaft _should_ be ok as far as length since the 9.5 pinion snout is only slightly longer than the 8.5, but you'll probably need a u-joint change to mate it together. Most 9.5's used a 1350 series u-joint. Many 8.5's used a 1310 or 1330 series.

Worthwhile swap on a 1/2 ton when they can be found.


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## 70monte (Feb 5, 2008)

The guy who owns this junkyard seems to know his stuff. When I asked how much the rearend was, he knew exactly what rearend was under that truck.

A few years ago when my 10 bolt was giving me trouble, I called some junkyards for a price on a 10 bolt and they all quoted me $650 for one. Of course I didn't call this current one.

Thanks for all of the info.

Wayne


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## PDQ Pete (Dec 22, 2002)

We can get a complete rear end for seventy five bucks at the local pick and pull. Took one out of a dodge van a couple weeks ago.


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