Towing and sucking gas like crazy.

[JayMB]

He's talking GAWR (gross axle weight rating).

Full floaters were optional on 8 lug 8600 LB GVWR 2500s. If you had a 350 (5.7 Vortec) they came stock with 9.5" semi floaters. Only the 454 and 6.5 diesel trucks were guaranteed to be 14 bolt full floaters with the 10.5" ring gear.

 

[Gibson]

He's talking GAWR (gross axle weight rating).

Full floaters were optional on 8 lug 8600 LB GVWR 2500s. If you had a 350 (5.7 Vortec) they came stock with 9.5" semi floaters. Only the 454 and 6.5 diesel trucks were guaranteed to be 14 bolt full floaters with the 10.5" ring gear.

Well, I've had 3 of the 8,600 GVW trucks, and all of them came with the FF 14bolt, and their was no option code for the FF in the data list.
They were standard equipment, and all were 350s.
Edit; one of them was a GMC, and for some reason it was 8,400 GVW,, but you know, GMCs are supposed to have lock washers on the bolts holding everything together.
But, Chevy/GMC have done lots of things over the years that don't show-up in the literature or codes.
I think that in the past a lot of trucks got shipped out the door with whatever stuff they had at the moment on a Friday afternoon.

 

[Supercharged111]

You got lucky. I don't know that the axle itself has an RPO, they may have included it in F44 or whatever the 2500s have for the heavy package. I've seen 8 lug 9.5 diffs, they do exist.

 

[White96k2500]

You got lucky. I don't know that the axle itself has an RPO, they may have included it in F44 or whatever the 2500s have for the heavy package. I've seen 8 lug 9.5 diffs, they do exist.

That’s what mine has, 8600lb GVW 8 lug,9.5”.

 

[Insert Quarter]

That’s what mine has, 8600lb GVW 8 lug,9.5”.

Same here, mine is a 89' C2500 5.7 8600GVW with an 8 lug 9.5" semi-float.

The C2500's I've seen (half a dozen maybe) that were 7200GVW all had the 6 lug 9.5" semi-float, and the 7200's that also had a 5.7L were 2 bolt main blocks.

The 8600GVW 5.7's I've seen all had 4 bolt main blocks.

Also, if you have an 8600GVW C2500 and can't find the correct rear leaf spring mount, it's because they used a K-series rear leaf spring mount, it makes the truck sit about an inch higher. I called Dorman because they had the part listed incorrectly on their website, not sure if they changed it though.

 

[White96k2500]

Same here, mine is a 89' C2500 5.7 8600GVW with an 8 lug 9.5" semi-float.

The C2500's I've seen (half a dozen maybe) that were 7200GVW all had the 6 lug 9.5" semi-float, and the 7200's that also had a 5.7L were 2 bolt main blocks.

The 8600GVW 5.7's I've seen all had 4 bolt main blocks.

Also, if you have an 8600GVW C2500 and can't find the correct rear leaf spring mount, it's because they used a K-series rear leaf spring mount, it makes the truck sit about an inch higher. I called Dorman because they had the part listed incorrectly on their website, not sure if they changed it though.

Mines a k2500, speaking of leafs though i need some lol.

 

[PlayingWithTBI]

Mines a k2500, speaking of leafs though i need some lol.

Here's a site you can plug in whatever you're looking for and, odds are, they'll have it.

https://www.sdtrucksprings.com/index.php?main_page=product_info&products_id=16899

 

[White96k2500]

Here's a site you can plug in whatever you're looking for and, odds are, they'll have it.

https://www.sdtrucksprings.com/index.php?main_page=product_info&products_id=16899

Thank you!!

 

[1997]

I think that in the past a lot of trucks got shipped out the door with whatever stuff they had at the moment on a Friday afternoon.

Thinking you're right, heck wasn't the original GTO built with what they had around,

You got lucky. I don't know that the axle itself has an RPO, they may have included it in F44 or whatever the 2500s have for the heavy package. I've seen 8 lug 9.5 diffs, they do exist.

maybe it depended on model, ie reg cab, extra cab, crew cab?

 

[Gibson]

I don't know that the axle itself has an RPO

Yeah, I used to have a book that a mechanic at a Chevy dealer gave me, it was about 3/4 inches thick.
It had all the option codes for everything going back into the '60s.
And yes, their was some number/letter for "Full Floating Axle" for the trucks and suburbans.
My present Sub is a K2500 with the 14 bolt 8 lug semi-float, but I've seen 2500s with the 14 bolt FF, it was an option.
Their was a "non catalog" option for Subs that were 9,2000 GVW, and they came stock with the FF, and they had the 3500 front end also.
If you took your time and really pick thru the pages, you could order a really special truck or Sub that no dealer would ever have in stock.