Leaf or coil standard rear spring on GMC?

[Fry]

My 1970 GMC sales brochure shows leafs as optional not standard. This is a Canadian brochure though if that matters.
My truck option list has G70 for “rear suspension leaf”.
It’s a stepside shortbox.

[54blackhornet]

Salesman guide shows leaf standard, coils optional. My 71 GMC 1500 has leafs and nothing showing on SPID.

[jocko]

Originally Posted by 54blackhornet

My 71 GMC 1500 has leafs and nothing showing on SPID.

That is THE data point. Thanks for checking.
If someone has a GMC with coils that also shows them listed on the SPID - that would pretty much close the case.

[72longstepper]

Unfortunately I do not have "original" glove box door as checking is not possible.

[Fry]

He’s a few pics of my sales book from 1970. Now Canada May be different than US built trucks. Clearly coils were standard here with leafs being the option.

[Mike C]

Originally Posted by 54blackhornet

My 71 GMC 1500 has leafs and nothing showing on SPID.

My big block 1/2 ton '71 GMC is on coils. And nothing shows on the SPID.

Now there is another data point. LOL

[jocko]

Originally Posted by Mike C

My big block 1/2 ton '71 GMC is on coils. And nothing shows on the SPID.

Now there is another data point. LOL

Yep, and a good one - we now have some conflicting ones!
Anyone got a GMC data book from any of these years?
I can't say as I've ever laid eyes on a GMC-specific data book.

[72 tigger]

A 70 1/2 ton GMC that l parted out a few years ago. It was on coils- shows HD springs- could a 1/2 ton have heavier coils?

[Fry]

Originally Posted by 72 tigger

A 70 1/2 ton GMC that l parted out a few years ago. It was on coils- shows HD springs- could a 1/2 ton have heavier coils?

Yes, see the option sheet I attached above. Shows same code for heavy duty leafs and coils option.

[72 tigger]

Originally Posted by Fry

Yes, see the option sheet I attached above. Shows same code for heavy duty leafs and coils option.

Thanks- surprising the hd coils are higher GVW than the hd leaves

[71 super]

My 70 cst bb swb Canadian built Chevy is factory leaf spring truck, was used to haul camper, and the red and white 71 super sb swb Chevy is also a leaf spring truck. List on spid for both.

[Mike C]

Originally Posted by 72 tigger

Thanks- surprising the hd coils are higher GVW than the hd leaves

Those are front springs on the SPID you posted and not rears as this thread was relating to.

[StingRay]

In Canada Chev and GMC 2wd were rear coils standard and leafs optional. Rear leaf in general up here are fairly rare. Longhorns of course always leaf but they were all really basically a 1 ton at heart.

[72 tigger]

Originally Posted by Mike C

Those are front springs on the SPID you posted and not rears as this thread was relating to.

Look on the left side- G50

[Coley]

So it is settled.....we are right after all.


...lol

[Mike C]

Originally Posted by 72 tigger

Look on the left side- G50

Oops. My bad! I was looking for the word coil which is there when it is something other than leafs if they are standard.

[davischevy]

Can somebody show me a GMC SPID with leafs on the truck and not on the SPID.

[special-K]

Originally Posted by jocko

That is THE data point. Thanks for checking.
If someone has a GMC with coils that also shows them listed on the SPID - that would pretty much close the case.

Refer back 4 years to post#8 where I laid it out straight and true. Data Schmata, I'm talking real life actual fact. Although the GMCs came through with leaf springs unless coil springs were ordered, the SPIDs still were printed showing the leaf springs as an option. And if the coil springs option was taken the SPID shows no option. You can take everything Chevy in regards to coil vs leaf on C/10 & C/20 and reverse it. You can look at any SPID on either marque and they will reflect the actual equipment but on GMCs you will be deceived into believing the leafs were an option and coils were standard. Can't always go by the book. I'd have to see that data book where that member claims it says coils were standard on GMC. Or did he say his books are Canadian? That too was laid out straight and true by another 'Canadian' member by stating the Canadian 910-930 trucks were actually Chevys with GMC trim. For instance, in 67-69 V6 was never offered like they were on US-built GMCs. GMC 910-930s were truly Chevrolets with GMC trim. In the USA, the 67-72 1500-3500 were the last of the truly different trucks (in drivetrain) with a lot in common.

Originally Posted by davischevy

Can somebody show me a GMC SPID with leafs on the truck and not on the SPID.

Nope, never happened

[SD69C10]

After reading through this I was hoping to get more clarification with my 69 C10 but I feel a bit more confused. Please excuse my ignorance as I am new to owning my truck and am trying to learn as much as I can...my confusion is that my long bed appears to have BOTH coils and leaf springs for the rear suspension. Is this an uncommon thing? Thanks for any help

[factorystock]

This is were we need to be year specific and assembly plant specific, many a times, we start throwing out info, without knowing any history of the vehicle. The Canadian built pickups always throw a monkey wrench into the discussion. First post says nothing about year, and a Canadian sales sheet to boot. Almost like Dana or corporate axles in a GMC?

[BROWN 70]

coils and factory overloads. g60 and g50 BROWN 70 ps built in fremont ca.

[CABLESCUM]

I always heard the same. Chevy-coil/GMC-leaf...option to change. Mine is a 72 GMC Short Step with coils. I know the original owner(I’m #2), and I know nothing was changed. The SPID lists “heavy rear springs”...

[71CHEVYSHORTBED402]

I know an old thread, miss some of these guys, including SStim, who hasn't showed his head 5-6 years now.

Looks like this has been beat with a dead horse over the years, perhaps adding confusion however...... I learned nothing reading through this thread and 1-2 like it, beyond it's confusing though maybe there's a dose of clarity into these murky waters.

I think the gist is for C10's built in the USA is:

A. Perhaps conflicting with GM's "clarification" document below, C10s were generally built with rear leaf springs, just cuz, and show a leaf spring RPO on the SPID.

B. Rear coil springs were standard in C10, which is RPO G50.

Not sure on years though, a change seems to have occurred in 1971. Perhaps that change was coil springs became standard in C10 Chevy, but not in C10 GMC, just cuz.

[Mike C]

I think one that that I don’t remember being referenced is that over time GMC became much less it’s own thing and much more just like the Chevy’s. So a ‘72 GMC is most likely equipped almost exactly as the Chevrolets while a ‘69 is more likely to be more of its own thing. Whatever that is.

I have owned 4 C2500 GMC, and they all have different GVWR and they all had leaf springs. They also all had Dana 60 rears. A 69 small block TH400, a 70 Longhorn small block SM/465, a 70 250 3 speed, and a 70 Sierra Grande 402/TH400. None of them had Leaf Spring on the SPID.

And then I have the 71 C1500 which is on coils. It’s a 402/TH400 truck and spring type is not listed on the SPID, but that jives for a Chevy of that same vintage.

My ‘69 short step C10 is a leaf spring truck with 307/TH350 and it is on the SPID. A parts 69 short step I have is a 250/3 speed truck on coils and they are not on the SPID.

So earlier GMC seem to follow the leaf thing and the later ones seem more likely to be coil in my small sample informal analysis.

And the Canadian trucks? Who the heck knows what’s going on there.

[58 Special]

Hauled a 71-72 C10 out of the bush last year. Glove box door was gone. Well optioned truck but mostly stripped. Was a leaf spring truck.