Topic: 66 shelby leaf springs

[dan green]

Are these original for a 66 Shelby?  I have never seen this type of leaf used on original ford springs.  Maybe they have been re-leafed?  Did Shelby do this?

[Bob Gaines]

Are these original for a 66 Shelby?  I have never seen this type of leaf used on original ford springs.  Maybe they have been re-leafed?  Did Shelby do this?

I havn't seen that type used on a 66 Shelby before. Maybe someone else has a different observation.  The leaf style and straps are not typical to what we normally see.   I don't think the date code supports a 66 ether. The date code appears to be a fairly early 1964 . I don't think they came off of a Shelby originally.Bob

[J_Speegle]

Wrong engineering number for a Shelby spring and agree - never seen this style of leaves and clamps before on an original application

[dan green]

It's hard to say what a previous owner or a shop that worked on the car may have done.  This car (#455) was repainted in about 1973 by the owner at that time whom I have spoken to.  These springs have the repaint over spray on them so I would guess that they were installed before that time.  I thought it is interesting that the springs if replaced have a ford leaf in them. 
How hard is it to find a set of original springs with the correct engineering numbers?

[J_Speegle]

It's hard to say what a previous owner or a shop that worked on the car may have done.  This car (#455) was repainted in about 1973 by the owner at that time whom I have spoken to.  These springs have the repaint over spray on them so I would guess that they were installed before that time.  I thought it is interesting that the springs if replaced have a ford leaf in them. 

May just be a service replacement from some known vendor or the usual supplier changed designs during that time period. Lots of possibilities IMHO

How hard is it to find a set of original springs with the correct engineering numbers?

Not too bad for just the engineering numbers - look of a Mustang with GT suspension since the springs were not any different on Shelbys

[s2ms]

Based on what I see in the MPC these, or at least the bottom leaf with Ford numbers, are 64-65 Falcon springs. The 66 GT350 rears have a C4ZA number...

Dave

[MattDoscher]

Adding to what s2ms said, 5556-T is a 4 leaf, 610lb load rate spring found on 65/66 hardtop Mustangs w/ 6cyl & 8cyl, 260, 289-2V, 289-4V.

[dan green]

What should the numbers be for a 66 shelby?
C4ZA & 55?? ?.  And a date code.

[MattDoscher]

I believe it should be C4ZA-5556-K, L, S, Y which is a 4 leaf, 650lb load rate for 65/66 FB & conv., 8cyl 289-4V HIPO.

[J_Speegle]

What should the numbers be for a 66 shelby?
C4ZA & 55?? ?.  And a date code.

We would need to know a Ford VIN (just the first 3 or four of the sequential) You can PM or email them to me if you would rather not post in public - I've got at least a couple hundred from other 66's so I might be able to guess from the Shelby VIN

I believe it should be C4ZA-5556-K, L, S, Y which is a 4 leaf, 650lb load rate for 65/66 FB & conv., 8cyl 289-4V HIPO.

Matt did you get those from the Master Parts Catalog? 

If so those are what would work as a replacement not what would be original to the car.

[s2ms]

Here is an original spring from 6S1757....

Dave

[MattDoscher]

Matt did you get those from the Master Parts Catalog? 
[/quote]

I was referencing pg 261 of my Mustang '64.5 - '73 Restoration Guide 2nd ed. by Corcoran & Davis.

[J_Speegle]

Here is an original spring from 6S1757....
Dave

Thanks Dave for another data point for my spread sheet.

Don't get allot of spring dates since they are so often swapped out over the years as they weakened.

Dates are always interesting since some parts were produced in an on going basis while others were produced in batches, likely due to demand or the machines that produced them. Our cars are over 10,000 numbers apart (Ford VIN) while the spring dates are weeks apart

I was referencing pg 261 of my Mustang '64.5 - '73 Restoration Guide 2nd ed. by Corcoran & Davis.

- Same thing since the MPC (likely 75 version) is where they took their information for that book from

[dan green]

Taking into account sheet metal dates on the car I would guess the car was built mid to late November 1965.
So I should look for springs with an October date?

[J_Speegle]

Taking into account sheet metal dates on the car I would guess the car was built mid to late November 1965.
So I should look for springs with an October date?

You'll be looking for the C4ZA-S springs

Looking at other examples (with tight spring to sheet metal date) I would look for ones stamped at least a month prior to the sheet metal dates. Maybe something between 250-290 but anything close should work

Remember the dating format is 234 E 5 - with

234 being the day of year - Julian year

E being the supplier

5 being the year

A usable site for figuring out the numbering system http://amsu.cira.colostate.edu/julian.html

Hope this helps