Topic: 67-68 Rear Leaf C77A-AR Spring Clamp Eye Changeover

[Bossbill]

In the leaf spring marking discussion for 67-68 Bob Gaines was surprised to find my Mar 67 SJ Competition Spring  -- found with Orange paint after a thorough cleaning -- also had square leaf spring clamp eyes. Sometime in 1967 the manufacturers of the springs  changed from square eyes to round eyes. The eyes are the part of the spring clamp over which the tab bends.

My spring codes are
C77A-AR
040EC7 (40th day of 1967, Mfr Plant 'E')

Canvasing others to see when a switch occurred from square clamps eyes to round clamp eyes.

[J_Speegle]

Added the spring number so we can focus on just one application. Different springs may have different results. We can always expand it later. 

Bob's likely busy today

[J_Speegle]

My challenge given what I have to work from is that I didn't record all of the engineering numbers to go with all of the pictures I have so do I post my finishes based on the matching orange paint marks  and what I have recorded as being -AR springs or only on the ones I have records of as -AR springs though not all of those have the matching orange markings?

[Texas Swede]

The original rear springs on my 67 GT500, #1317 both have C7ZA-5556-AM
and both dated 298E6.
Texas Swede

[J_Speegle]

The original rear springs on my 67 GT500, #1317 both have C7ZA-5556-AR
and both dated 298E6.
Texas Swede

Clamp design ?  Square or round

Thought yours had the -AM rear springs from another post elsewhere. Must have written it down incorrectly 

Yours is the earliest date with those springs that I have record of. Have other examples around the same time and with the same spring date but with -AMs

[J_Speegle]

Here are three examples I found where I had -AR spring info and pictures of clamps. All with square clamps

67-2134



67-2935 The springs on this example had been restored so the clamps could be suspect



67-3206 The springs on this example had been restored so the clamps could be suspect


Interesting differences in the orientation of the stamping of the engineering number on the springs though all came from the same spring plant it appears.   Also it appears that the spring plant inventoried some early dated springs for a fair amount of time or at least one pallet worth as I have a couple from this date late in the year.

[Texas Swede]

Sorry Jeff, I had the numbers written down on a note and got it wrong.
They are indeed AM. I changed my post. Can't check the clamps as my car
is in Sweden so you have to wait about 3 months.
Texas Swede

[Bob Gaines]

In the leaf spring marking discussion for 67-68 Bob Gaines was surprised to find my Mar 67 SJ Competition Spring  -- found with Orange paint after a thorough cleaning -- also had square leaf spring clamp eyes. Sometime in 1967 the manufacturers of the springs changed from square eyes to round eyes. The eyes are the part of the spring clamp over which the tab bends over.

My spring codes are
C77A-AR
040EC7 (40th day of 1967, Mfr Plant 'E')

Canvasing others to see when a switch occurred from square clamps eyes to round clamp eyes.

Actually I was thinking knowing you had a earlier production car that it was very early to have square. It was more typical to see the round early and square later. I have seen a lot of 65 and 66 SJ cars with round also. The cars I was seeing in those time frames with the square ones I am not sure if was a different variation that was also used or replacements. My be Jeff can look through some of his SJ pictures.

[Bossbill]

Didn't realize that early had round eyes and later had square eyes. Although I have two 65s, neither has a stock spring.

Looking at Paperback Writer's chart it "looks like":
Early GT350s (Competition handling-625lb):C7ZA-AN
Later GT350s (Competition handling-625lb):C7ZA-AR

Early GT500s ((Competition handling-665lb):C7ZA-AL
Later GT500s ((Competition handling-665lb):C7ZA-AM

So Texas Swede's GT500 wouldn't even be in the discussion of the 'AR' spring.
It would stand to reason that Jeff's pictures are all GT350s.

Is there any inference that the -AN and -AL were round eyed?

[Bob Gaines]

Didn't realize that early had round eyes and later had square eyes. Although I have two 65s, neither has a stock spring.

Looking at Paperback Writer's chart it "looks like":
Early GT350s (Competition handling-625lb):C7ZA-AN
Later GT350s (Competition handling-625lb):C7ZA-AR

Early GT500s ((Competition handling-665lb):C7ZA-AL
Later GT500s ((Competition handling-665lb):C7ZA-AM

So Texas Swede's GT500 wouldn't even be in the discussion of the 'AR' spring.
It would stand to reason that Jeff's pictures are all GT350s.

Is there any inference that the -AN and -AL were round eyed?

As far as 67 Shelby's go earlier cars typically got the AM springs and the later cars got the AR springs regardless of if GT350 or GT500.

[Bob Gaines]

Here are three examples I found where I had -AR spring info and pictures of clamps. All with square clamps



Interesting differences in the orientation of the stamping of the engineering number on the springs though all came from the same spring plant it appears.   Also it appears that the spring plant inventoried some early dated springs for a fair amount of time or at least one pallet worth as I have a couple from this date late in the year.

Jeff, I think you will find that the leaves that had the stamping cross ways were typically 67 and the leafs that were long ways were typically 68's maybe change happen in late 67 but I have typically found the long ways stamping on 68 production cars.

[Bossbill]

As far as 67 Shelby's go earlier cars typically got the AM springs and the later cars got the AR springs regardless of if GT350 or GT500.

That's really odd given that the 390s got the 665lb  spring (according to the chart/MPC) and GT500 Shelby's didn't?
Yet another Shelby oddity that flies in the face of logic.

[Bossbill]

Jeff, I think you will find that the leaves that had the stamping cross ways were 67 and the leafs that were long ways were 68's maybe change happen in late 67 but I have typically found the long ways stamping on 68 production cars.

And yet my early February (040) springs are long ways. And so is Jeff's pic of a late February (050) spring:


Very confusing ...

[Bob Gaines]

And yet my early February (040) springs are long ways. And so is Jeff's pic of a late February (050) spring:


Very confusing ...

Yes it is . The E stands for Eaton maybe more then one Eaton plant that produced them .

[J_Speegle]

Jeff, I think you will find that the leaves that had the stamping cross ways were typically 67 and the leafs that were long ways were typically 68's maybe change happen in late 67 but I have typically found the long ways stamping on 68 production cars.

I don't disagree but just showing what I have pictures of related to the specific spring numbers. Obvious that is why we used thew word typical as it doesn't mean always   As these early 1967 springs show.

If we branched out we would likely find more examples of the stamping applied "cross ways" 

Did a quick look through about a third of production (not all having detailed pictures of the spring clamps) and I did find other original springs (other markings) with the square style clamp holes. So I think the best we can do is to suggest that if an owners/builders  springs or clamps have been replaced go with what was more common as we always have suggested with any of the details

And yet my early February (040) springs are long ways. And so is Jeff's pic of a late February (050) spring:
Very confusing ...

Not sure why there is confusion. They were stamped both ways and yours being dated  (040)  Feb 9th  and the one you picked out (050)  dated Feb 19th