Topic: 67 GTA 289 Coupe, Spring Codes and Markings, San Jose

[ruppstang]

Probably not much help but here are the springs on our 11-04-66  GTA convertible.

[67gta289]

Marty, to be clear is that a 289 convertible?  AC? Thermactor?  Just in case we put a document together. Thanks, John

[ruppstang]

Yes a convertible 289 w/ AC no thermactor.

[196667Bob]

Before we get any deeper into "what spring goes with what package (Option)", I believe that in order to avoid any further confusion, at least for me, we need to get "availabilities" straightened out (while right now we are concentrating on the rear leaf springs, the comments also apply to the front coil springs).

For 1967, I see 4 different choices :

1)  "Standard", Regular Production Springs for each Body Style.

2)  "Heavy Duty" Springs that were part of the "Special Handling Package" that was
      included with the GT Option.

3)  "Extra Stiff" Springs that were included with the "Competition Package" , which
      could only be ordered if the GT Option were ordered.

4)  "Springs" that were part of the "Heavy Duty Suspension" Option, which apparently
     could be ordered for any car, regardless of engine.

These four choices bring with them, a couple of questions :

1)  Were the "Heavy Duty" Springs furnished with the GT Option, the same as the "Springs" furnished with the Heavy Duty Suspension" Option ?

2)  Does the "Improved Handling" designation noted in the MPC's refer to the Springs
     furnished with the GT Option or those furnished with the Heavy Duty Suspension
     Option, or to both ?

It seems like the only way to get the answers to these questions is by using both the Marti Report and the Build Sheets from a vehicle being "investigated". I say this because my "guess" (since I do not have any of the three suspension Options), is that the Marti Report would only list the Option, not its specific contents. Has this been done before ?
If not, doing it in itself may be a challenge. As Jeff noted, many changes were made between the printings of the MPC's ; 1967 Only (January 1967), 1960-68 MPC (April or August 1968), and 1965-72 MPC (May of 1975). While I have at least one OSI (Obsolete-Superceded-Interchange) Book from every year from 1961-1974, plus 76,77,79 and 81, they only reference Part Numbers,. not Casting/Marking Numbers. So, as long as the Part Number changed along with the specific contents (which is usually, but not always the case), we can track the changes that occurred between the MPC printings. Although I have never seen one, it would be helpful if there existed a chart, like those shown in the MPC's, that related the Spring Part Numbers to their marked contents, for the changes that occurred between MPC's.

Any documented help in resolving these questions will surely help in our further pursuit of the Spring applications.

Bob

[67gtasanjose]

In my searches over the weekend, I came across these REAR Springs that look to have the correct date code on them. They are claimed to be off of a coupe and the car they were removed from is from Southern California, but no other details known at this time. Looking at the charts, I do not find the C7ZA-Y Springs listed. I noticed the numbers are stamped into the Springs sideways when compared to other examples shown so far.

[67gtasanjose]

So I did look at my front springs and I think we are on the right track with them. Both have orange and a light purple (violet) daubs down them. ( photos of violet is rather unpronounced).

This to say, I believe I already have the original front Springs in place and it looks to match what is shown in the chart posted earlier in the MPC.

Still looking to see if anybody can find any information about those C7-Y Springs I posted in my previous reply to this one.

Another thing I was noticing while looking at some of the MPC pages that have been posted on the coil springs, in the footnotes at the bottom of each page there indicates a daimond symbol, and an open diamond indicates "improved handling" while a closed or filled in Diamond indicates "racing only". For the rear leaf springs, it is spelled out if it is improved handing or competition suspension. Further, there looks to be NO front coils for SMALL BLOCKS with "Improved or Competition" (unless I am missing something)

[J_Speegle]

So I did look at my front springs and I think we are on the right track with them. Both have orange and a light purple (violet) daubs down them. ( photos of violet is rather unpronounced).

Great

Still looking to see if anybody can find any information about those C7-Y Springs I posted in my previous reply to this one.

I have examples of the -Y being used on standard suspension (non-GT) small block auto applications. The details on the spring match buildsheets of the matching time period so believe that is what they were originally install on so it does not look like they were the original ones for your application

Another thing I was noticing while looking at the MPC pages that have been posted, in the footnotes at the bottom of each page there indicates a daimond symbol, and an open diamond indicates "improved handling" while a closed or filled in Diamond indicates "racing only". For whatever it is worth, neither of these appear to have been used in any of the listings of the MPC for any small block applications for a 1967.

Guess your referring back to the front spring section now. Yes not sure why Ford choose to do that since we know they built and sold parts for those applications. Will take a look at the earlier 68 version to see what they have there related to this specific detail

 Have also found where the symbols shown at the bottom of the page (in other sections and versions)  do not always exactly match what is used in the charts but they are sometimes similar. Guess they expected the counter workers to figure it all out

[196667Bob]

Richard : This one took a little digging. In looking at the 1965-72 MPC (copy attached), I found that the C7ZA-5556-Y Spring was replaced by Springs C4DA-5556-U, C7ZA-5556-M, and/or C7ZA-5556-Z, the whole Spring Assembly now being noted C4DZ-5560-J (this assembly was originally shown for a 1964 Falcon with either 6 cylinder or 260 V8 ; it obviously would have only included the C4DA-5556-U Spring). While this shows the disposition of the C7ZA-5556-Y Spring, it doesn't show from where it came.

Time for a little "Reverse Engineering". I started with the 1966 OSI to see if the C4DZ-5560-J replaced a C7ZZ Spring Assembly. Nothing in the 1966,67 or 1968 OSI's. But in the July 1969 OSI, it shows that the C7ZZ-5560-B was "Replaced By" the C4DZ-5560-J. So it can be said that sometime between July 1968 and July 1969, this occurred. At this point, I went back to the 1960-68 MPC to see what it noted for the C7ZZ-5560-B Spring Assembly ; lo and behold, it shows that Springs that made up the Spring Assembly were C7ZA-5556-M and or -Z. I then went to my 1967 "Only" MPC, and it also shows that the C7ZZ-5560-B included the C7ZA-5556-M and/or -Z Springs. Based on these findings, since the "-M and -Z" are shown as replacing the "-Y", one can now make an "educated guess" that the "-Y" preceded them ; specifically, sometime between the initial production of 1967 Mustangs, and January of 1967.

To continue this "exercise", I decided to check the OSI's that followed, up through 1974, to see if any other changes occurred prior to the May 1975 printing of the 1965-72 MPC.
Below is listed what I found in each year OSI that was checked :

JULY 1970 - C7ZZ-5560-B r/b C4DZ-5560-J
                                      C7ZZ-5560-C r/b C7ZZ-5560-M
                                      C7ZZ-5560-D r/b C7ZZ-5560-N
                                      C7ZZ-5560-K r/b C7ZZ-5560-T
                                      C7ZZ-5560-N r/b C7ZZ-5560-M
                                      C7ZZ-5560-U r/b C7ZZ-5560-T
                                      C7ZZ-5560-L  NR

JULY 1971 - Same as 1970

JANUARY 1972 - Same as 1971 PLUS
                                             C7ZZ-5560-J r/b C7ZZ-5560-M

JULY 1974 - Same as 1972 PLUS the following :
                                      C7ZZ-5560-G  NR
                                      C7ZZ-5560-H  NR
                                      C7ZZ-5560-R  NR

From here, the 1965-72 MPC "takes over". I did not continue beyond it.

So Richard, I hope this explains where the C7ZA-5556-Y fits into the picture.

As I mentioned in a previous Reply, OSI books only include Part Numbers, not marking or casting numbers. Thus trying to track the existence of a certain part can be laborious. In this "exercise", I used the 1967 Only MPC,  the 1960-68 MPC, the 1965-72 MPC, and 8 different OSI's. In this case, I was able to relate the Part Numbers to the Spring marking numbers as they were actually noted under the different Part Numbers in the MPC's. Many times they mat be listed in one source, but not in another, and sometimes, not at all.

Personal Note to "67gta289" - John : This is a perfect example of the use and benefit (at least in this case) of the OSI's.

Bob

[J_Speegle]

Interesting Bob and thanks for taking all that time (been there done that) going through the books.

It is interesting that Ford took 5 years before they saw a need to include the -Y in a MPC. Kind of odd nut its there.  Since the M 7 Z marked springs were being used to replace the Y spring we can guess that the original rating of the Y spring was the same or similar and in turn supports the other finding that it was the low or standard rear spring - not one that was installed on GT, GTA or comp suspension cars. So we have a three way match from documentation.

Unfortunately that puts the OP back searching again

[67gtasanjose]

Went back and cross referenced  known cars, paint markings, spring numbers and the MPC and I can see where this got a bit jumbled for me.

Here is a picture of a page from April 68 MPC. You will notice that the ordered that the info is presented is standard, for competition handling GT only then & improved handling only. Its interesting that the and sign was inserted between the engine size and the suspension description in the improved section but not in the other two.  This difference in order may have added to my confusion.

Now to confirm the applications I took spring numbers from know cars (taking into consideration options and accessories) and they seem to match in all but a couple of examples. Apparently one set of data may have come from a comp suspension car that I and the owner did not realize.  Seems a bit strange to have located a fair number of these very rare cars. 

There are a couple of springs used in 67 production that are not included in any of the MPC's  and there is no mention of the substitution or replacement but realize that the real guide to this is a separate/book book that shows casting numbers and conversion (new) part number that was published often. Right now can't find anything that shows application for C7AZ-Y and C7AZ-AY

Another thing that added a twist is export cars with the improved or standard suspension parts.

So as right now my understanding that for this exercise and for rear springs 
"improved" equals GT and GTA application in 67 while & competition handling GT  equals Shelby's and cars ordered with competition suspension.

Here is a picture of the April 68 page for rear springs




So in an attempt to find an answer to your first question would you agree that your car likely/possibly came equipped with rear springs marked C7ZA-5556-AU or AV? 

Believe the "C7ZZ" is just a typo

So, (Re: Rear Springs), can we assume that "Improved Handling" springs should be found on ALL GT's & GTA"s?
...WHY SO MANY DANG CODES?

I understand the goal would be the "desired ride height" (particularly in rear) more than how the springs "jounce" since the shock absorbers handle that aspect more than the springs would. (excepting Competition Suspension, no doubt a much stiffer ride).

[ruppstang]

IMHO this is why it is so much easier to restore a car back to what it was instead of what you want it to be if you want it to be correct. I understand you goals, just a tough road.

[67gta289]

Marty, I'm pretty sure that Richard's car is an original 289 GTA coupe, but the original rear springs are gone, so he is looking to make it correct.  The original front springs, due to lack of stamped part numbers, might be right, might be wrong, so he is looking for evidence to make sure it is right.  I don't think he is restoring the car to something it wasn't.

I do agree it is easiest to restore a complete vehicle back to original.  Next up would be restoring a car back to original that is missing some key pieces.  Making up a car as a tribute or something would be painful to do right, if there is such a thing as right in that regard.

[67gtasanjose]

Marty, I'm pretty sure that Richard's car is an original 289 GTA coupe, but the original rear springs are gone, so he is looking to make it correct.  The original front springs, due to lack of stamped part numbers, might be right, might be wrong, so he is looking for evidence to make sure it is right.  I don't think he is restoring the car to something it wasn't.

I do agree it is easiest to restore a complete vehicle back to original.  Next up would be restoring a car back to original that is missing some key pieces.  Making up a car as a tribute or something would be painful to do right, if there is such a thing as right in that regard.

Both of you are correct in general understanding as I have shared with both of you the desires of my goals.

I had been researching the springs I had on hand, I was pretty sure the fronts were original and the rears were not. The front coil springs were confirmed because of information shared in this thread. They DO HAVE the the violet & orange markings.

The REAR springs have been the last issue to resolve. I cannot un-do the decision years ago to replace them if I do not understand what was at least INTENDED to be there. So far, best match I have located is the correct dated C7-Y springs. It would be nicer to find ones date correct, confirmed through similar build info and with codes that can be confirmed through the charts provided within this thread as 665lb.? load ratings (codes: AS, AT, AU, AV). Obviously, the springs installed at the assemblylines varied (e.g. running changes) over the model year making this search (as Jeff put it earlier) going in circles.

[ruppstang]

I found that I have a pair of these Y springs from a coupe and I also have a AU.

[67gtasanjose]

I found that I have a pair of these Y springs from a coupe and I also have a AU.

Dated May '67 so the suggestion Bob had about being obsoleted by January has "issues".

Marty, the "AU" you have, just one?