I’ve been having a memory lapse on what year rearend I have under my ‘57. I bought it from a wrecking yard in the late ‘70’s. I’m kinda thinking ‘66 or so? I looked where I thought I stashed a set of new brake cylinders for it and shoes, but alas they walked off sometime in the past 40 years, and now I need them!
GMC used leafs with the Dana rear even in the 67-72 trucks, didn't they? chevy had coils with their rear during those years. Do some measuring while you are looking up the parts on rockauto.com, and see what you can find. The major difference was the drums, the GMC drums are offset about 1/4" different than chevy drums, which causes all kinds of mayhem. I have a 1965 GMC dana rear in my 59 Chevy pickup....btdt.
Check here: gmheritagecenter.com Look in the vehicle information kits.... They give manufacturer's specifications for everything GM has ever built!!! EDIT: Just looked at it again...They've taken down much information. Still have Cadillac, Chevrolet (car/truck), Olds and (cough) Geo.
To my knowledge GMC never used rear coil springs as standard equipment. Chevy used rear coils in 1/2 and 3/4 ton from 60 through 72. There is no viable GMC info on the GM Heritage site for 60/72 and very little at all. Chevrolet trucks are well covered but not GMC, never assume without checking your facts. There is no GMC info T all in the information kits. I think you could get rear leaf springs on some Chevy trucks either certain equipment in the 60_72 year models.
GMC was coil then leaf ^^^^^ (look at Squirrels post). Chevy was coil from 60 to 72 (on the 1/2 ton). This standard, you could get the optional setups (leaf Chevy, coil GMC).
Meaning when the torsion bars went away GMC went back to rear leaf springs. I had a 64 1/2 ton Gmc that was leaf. I used it for much work truck for a couple of years.
Maybe my memory is off. It’s a 12 bolt rear with 3.08’s. I “think” I recall the counter guy saying “you can only get 3.08’s in a GMC rearend”. I might be mixing up trucks and projects over the years. I’ll pull a drum this weekend and try to match it up on RA.
Dana used 3.08 ratio, Chevy cars used 3.08, Chevy trucks used 3.07 If it's 12 bolt rear from a truck, the brakes shouldn't be too hard to find parts for. Just look and see what you have on it....they used 2" wide shoes until the early-mid 70s, then they went to the larger ones.
Jim, it could be a 3.07 as well. It’s for sure a pickup rear (6 lug) non-posi. I guess the memory is one of the first things to go
There aren't a lot of options on That general era of GM brakes like some models. There is a pretty good chance that the shoes are 11X 2.
my 63 chevy had 373 gears, a buddy had a 64 gmc and it had 411 gears with a 6 banger. mine has coils, his was leafs.
Dont forget that in 71 Chevy when they went to 5 lug also had a leaf option/standard on there 1/2 tons. I remember back in my junk yard days that a coil 5 lug was tough to find...
You are all correct about failing memory but I've owned many 48-72 Chevy and gmc trucks. If my memory what's left of it, in the 67-72 GMC s you could get either rear end as ive had both
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