k2500 8600gvrw trucks tow ratings have gotta be under rated

[seth9199]

im pretty sure 7500lbs is more like 1500 numbers these trucks should be able to tow 10,000lbs easy. so my question is whats holding them back from pulling more?

 

[Lanny]

Well if you're asking why GM didn't rate them to tow more, probably because they tested and designed them to safely and reliably tow that weight. Will they tow more? Sure, just don't tell your insurance company or the D.O.T.. And make sure you have good brakes.

 

[tachrev]

Cooling systems and power.

The 454 trucks were rated to bumper pull 10K if equipped with 4.10's. 8500 or so with 3.73's.

350 trucks had the lower 7500 rating with 4.10s, I believe.

The only major difference between the two 2500 trucks (if both equipped with 4.10 gears) is the radiator, and the power output.

Same brakes, suspension, transmission, rear, etc. I believe the 350 trucks had the 17x34" radiator, not sure how many cores. 454 trucks had the 19x34" 2 core radiator.

 

[b454rat]

Ugh, alot more than that. There is a lot of differences between a 350 equipped truck and a 454. 350 trucks came with the smaller rear, brakes might be same size, rear springs thinner or less springs, smaller radiator. The 454 trucks had the full float rear, HUGE radiator, 13" drums. The biggest thing with towing capacities is brakes. **** I had an S-10 pull my old man's old truck, (98 K2500HD ECLB 454 6" lift 35s) when his starter took a ****. It would pull it, but no way in hell would it stop it.

 

[454cid]

Unless the 2500 used a different radiator than the 3500, I'm pretty sure it was a 3-core. My Delphi replacement is definitely a 3-core. It came from the Harrison Radiator plant in Lockport, NY. Wide 2-cores are what companies are doing now.

 

[tachrev]

Unless the 2500 used a different radiator than the 3500, I'm pretty sure it was a 3-core. My Delphi replacement is definitely a 3-core. It came from the Harrison Radiator plant in Lockport, NY. Wide 2-cores are what companies are doing now.

Just ordered on for a 2500, it was a 2 3/16" thick 2 core 19x34. I looked up the 3500 as well and it was the same radiator.

I thought you could get the 350 trucks with a FF rear...maybe that is only in the 3500's. There are so many combinations on these trucks its hard to keep track.

 

[b454rat]

Buddy bought a 98 I believe new. Had a 350, 5-speed and the full float rear. 2wd. Almost bought a 98, ECLB, SAS'd, 350, 5-speed, semi float rear. GM did some weird **** with these trucks. Most of the 350 trucks Ive seen had a smaller radiator than a desiel or 454 truck....

 

[L31MaxExpress]

Just ordered on for a 2500, it was a 2 3/16" thick 2 core 19x34. I looked up the 3500 as well and it was the same radiator.

I thought you could get the 350 trucks with a FF rear...maybe that is only in the 3500's. There are so many combinations on these trucks its hard to keep track.

Not sure on the truck situation but my 10.5 FF came out of an 8-lug 2500 4.3 van. It was a 4.10 gear and had a G80 from the factory. Had the biggest brakes (I believe 3.5" wide) you can get on a SRW truck just smaller wheel cylinders.

 

[Supercharged111]

From what I've seen, the 2500 got a taller radiator than the 1500 and the 3500 got the same 19" tall unit as the 2500 but a lot thicker. I think all diesels got the huge radiator no matter what. I tow around 9000 enclosed with my modified 1500. I imagine a real 2500 would be that much better with the added weight of a longbed and rigidity of the thicker frame. It'll tow more than 7500 safely. My owner's manual has the 2500 rated to tow less than the 1500, so GM's logic here is simply not to be trusted.

 

[tachrev]

From what I've seen, the 2500 got a taller radiator than the 1500 and the 3500 got the same 19" tall unit as the 2500 but a lot thicker. I think all diesels got the huge radiator no matter what. I tow around 9000 enclosed with my modified 1500. I imagine a real 2500 would be that much better with the added weight of a longbed and rigidity of the thicker frame. It'll tow more than 7500 safely. My owner's manual has the 2500 rated to tow less than the 1500, so GM's logic here is simply not to be trusted.

The ratings are a little odd.
But the lower rated trucks where the 5.7 trucks. My towing experience is all with a 1500 350, so a little different. But the same rated power, so I can speak to that.

But I have done a LOT of towing with our old truck. The 350 is a great engine, but stock you will slow down a lot with any real grades.
My old 1500 had mandrel bent catless pipes to get rid of the terrible bottleneck in the stock cat pipes. That was about it for "power improvement". It did have an HD fan clutch so that probably sucked some power. 3.73 gears. Stock size tires.
With our 6500GVW camper there where some long grades where I could do 40-45mph MAX, in 2nd, foot to the floor. But we don't have the elevation here in the east that people have to deal with out west, so I could see a 5.7 truck having a lot more trouble on a "real" mountain and not our baby Appalachians.

A 2500/3500 would be even slower. Weighs more to start with the bigger diff's and trans. 4l80 sucking more power. etc. 4.10 gear are a help though and obviously it will had way more abuse.
I loved my 350 but stock (which is what GM rated these trucks at) they are simply down on power.

Supercharged111, you truck has a bunch more power than stock, so you done have that problem.

Our new Suburban is a 74 with 4.10's, so I am looking forward to comparing the two. We'll be towing the camper with ti this weekend, but no hills so not a real test.