Were GMC leaf springs an option?

[rscam]

I have heard that GMC had leafsprings standard and you could option for coil overs. Chevy was the other way. I have a 69 GMC and the spid says under the options G70 for leaf springs. Can someone more learned than me explain this?

[bigblockV6]

From 1963-68 GMC did not offer rear coil spring suspension, they actually didn't like the way it worked because suspension travel was limited. By 1969 rear coils were available again but this was due to some GMC trucks and all suburbans were being produced by Chevrolet.

[rscam]

So if Chevy built the truck they may have been thinking option for leaf springs instead of standard. That may explain the option code on the SPID.

[bigblockV6]

Originally Posted by rscam

So if Chevy built the truck they may have been thinking option for leaf springs instead of standard. That may explain the option code on the SPID.

Just for curiosity which assembly plant was your truck built? Check for these letter codes in your VIN: F,Z,P,S,J for starters.

[WorkinLonghorn]

G70 was a suspension package.2000 lb (each) leafs,12x2 1/2 brakes,HD shocks, 4.56 Dana rear (with certain engine/trans combos).

[rscam]

Another ? then. Why would that option be on a shortbed stepside. Seems like that would be a 3/4 ton option. The spid and the cab have the same vin. on them. I am going to go look at the frame and see if it matches the vin.

[StingRay]

In Canada all 67-72 Chev and GMC were typically coil but could be optioned either way.

[Longhorn Man]

69 was an odd year, coils were standard on 1/2 ton GMCs. I have a paper somewhere that I have posted a few times on here that shows this as fact.

[Blazer1970]

After reading many posts and threads on this subject, I am convinced that
all the '67 - '72 2wd half ton trucks (GMC and Chevy) came with coil springs standard. Leaf springs were an option as your SPID shows.

[bigblockV6]

Originally Posted by Blazer1970

After reading many posts and threads on this subject, I am convinced that
all the '67 - '72 2wd half ton trucks (GMC and Chevy) came with coil springs standard. Leaf springs were an option as your SPID shows.

Wrong!!!!! Other than GMC suburbans that were built by Chevrolet starting in 1967, 67-68 GMC pickup trucks came standard with leaf springs, rear coils were not available according to all the factory GMC literature, I never seen a 67-68 GMC with rear coils as well .

[bigblockV6]

Originally Posted by bigblockV6

Wrong!!!!! Other than GMC suburbans that were built by Chevrolet starting in 1967, 67-68 GMC pickup trucks came standard with leaf springs, rear coils were not available according to all the factory GMC literature, I never seen a 67-68 GMC with rear coils as well .

That excludes 67-68 Canadian built GMC trucks they were built by

[68350]

GMCs were ALMOST all leaf springs, however it was still an option. The coil was standard, just not par for gmc trucks.

[ed2552]

It was prolly a heavy duty package for the half ton vs the three quarter ton

[WorkinLonghorn]

Don't know why it was on a C10 but here's the C20 info in case nobody believes anything I say;

[rscam]

Engine is long gone but it was a 6cyl because of the vin. and 3.73 rear end, but according to that document it should have had a 4.56 rear. Its says 250,292,307 and 350 engines would have 4.56 gears. If I read it correctly

[rscam]

Also it has the 11" brakes. I suppose someone could have switched the rear axle. Does the axle have the vin like the frame,cab and SPID?

[WorkinLonghorn]

So does the frame VIN match the cab's?-or did I miss that post?

[Longhorn Man]

your GMC is a 1/2 ton. 3.73 is the base gear ratio for all 3 speed manual shift 1/2 ton trucks if memory serves... 4.56 is the base gear ratio for all 3 speed manual shift trucks in 3/4 ton.

[rscam]

C S 1 0C-1 A is the vin. 2wd 6cyl 1/2 ton fenderside. The GMCpauls gmc data dosen't list 1 for a plant but the Chevy data says 1 is Oshawa. where ever Oshawa is.

[rscam]

Also the vin matches on the frame, cab and Spid.

[Longhorn Man]

GMC decodes differantly than chevy, look here; (69 only, other years differ)

[Longhorn Man]

[togriff]

I've always heard that GMC all had leafs, and chevy had coils. But chevy also had leafs on the heave half tons , and leafs on larger trucks. I've never seen a GMC with coils. I've had alot of these trucks and still do, but I do have a Chevy 1/2 ton with leafs.

[67_C-30]

Originally Posted by togriff

I've always heard that GMC all had leafs, and chevy had coils. But chevy also had leafs on the heave half tons , and leafs on larger trucks. I've never seen a GMC with coils. I've had alot of these trucks and still do, but I do have a Chevy 1/2 ton with leafs.

I have had 2 GMC trucks that came with coils - a '69 and a '72. It does not list coils on the SPID, but every GMC with leafs I have, a '69, '70, and a '71 all have Leaf Springs listed on the SPID as an option... I also have a '67 3/4 ton, but it doesn't have a SPID, and looks like it never did. (original paint on the glove box door, no glue residue or scratching?)

[Longhorn Man]

there is no such thing as a heavy half untill the late 70's and by then they were all leaf.