Topic: 1968 San Jose GT 390 Fastback NOS Leaf Springs vs Repro

[Bob Gaines]

Thanks Bob I am with you 100%. Now where can I get the right bottom leaf?

First determine which one (suffix of engineering number ) is correct for your particular application and go from there . Unless it is a competition suspension car  (AR suffix ) it is not a insurmountable task. 

[bullitt68]

All of the NOS service replacement springs I have ever had were stenciled with a part number similar to the picture.They are typically a one size fits all type item. I would be surprised if the number stamped into the metal of the bottom leaf of the NOS set is the same as the one original to your car. You may want to confirm before considering making a offer for purchase. If they are not the same like I suspect then the value to you or for that matter anyone else considering the one size fits various applications status would be diminished over a NOS assemblyline set. In that case one of the close reproduction sets with a transplanted bottom leaf would make the most sense from a historical stand point IMO.   

Hio Bob these are the leaf springs that Scott Drake sells. I am wondering how close they are to original. Assuming to be correct the paint would need to be removed etc. Just curious about the rest of the details. I have been trying to get some photos of the Eaton spring for comparison. So far no luck. Also trying to confirm ride height etc.

[J_Speegle]

Not Bob  but the clamps look correct for the time period and plant but the short leaf is shaped differently from what was originally supplied

Yes look like they were completely painted once all assembled on these reproductions

[bullitt68]

Not Bob  but the clamps look correct for the time period and plant but the short leaf is shaped differently from what was originally supplied

Yes look like they were completely painted once all assembled on these reproductions

Thanks Jeff. If they look like the best op[tion I will order a set and disassemble and refinish in bare steel, treated of course and then try to source as stamped lower leaf. Just trying to get as close as I can as the guy with the NOS springs won't give me a price and just wants me to make an offer, but I don't see any point in paying crazy money for NOS springs. Some guys are looking to get crazy money for rare NOS parts. Clearly these are rare and his business is selling Mustang parts.

[Bob Gaines]

Thanks Jeff. If they look like the best op[tion I will order a set and disassemble and refinish in bare steel, treated of course and then try to source as stamped lower leaf. Just trying to get as close as I can as the guy with the NOS springs won't give me a price and just wants me to make an offer, but I don't see any point in paying crazy money for NOS springs. Some guys are looking to get crazy money for rare NOS parts. Clearly these are rare and his business is selling Mustang parts.

I concur with Jeff . I also agree that it would not make sense to buying the NOS set unless the bottom leaf matches exactly your application. I don't begrudge the seller trying to get the most out of it ether. Of course if it was the last completely correct part you needed on a perfect restoration it would command a premium.

[bullitt68]

I concur with Jeff . I also agree that it would not make sense to buying the NOS set unless the bottom leaf matches exactly your application. I don't begrudge the seller trying to get the most out of it ether. Of course if it was the last completely correct part you needed on a perfect restoration it would command a premium.

Agreed Bob. So far my understanding is that the only stamp on the NOS set is the paint stamp in yellow on the top of the spring and no actual steel stamp marking on the bottom leaf. I am not sure if the Eaton or the Scott Drake leafs are the most accurate as I have only received photos from Scott Drake. However if they look good and are my best option I will go that route and hope to find a bottom spring with a good stamp at some point. Hopefully once stripped and treated they at the very least will look correct. I have seen some guys running the paint stamp on the top of the spring like Scott Drake offers. Not sure if I would go that route or not, as it would mean that the part is a reproduction of an NOS part and not original. Perhaps it is a question of personal taste. I have seen the same thing done with sheet metal parts etc. My lower tail pan is an NOS replacement part, but I plan to paint red oxide primer over it so it would look fresh like the rust of the car.l Not even sure of the stencils are available or if you would have to make up your own. Do people even go to that level. I am not sure as I have not seen photos of high end cars restored to that level mainly just original examples to date. Perhaps if I saw some restored examples for comparison I would use that as a reference.

[J_Speegle]

/.....My lower tail pan is an NOS replacement part, but I plan to paint red oxide primer over it so it would look fresh like the rust of the car.l Not even sure of the stencils are available or if you would have to make up your own. Do people even go to that level.

For a restoration you would not want to have a stenciled part number on a panel since that would not have been there originally on a part installed at the car plant but would suggest to anyone viewing the car that the panel had been replaced later

I am not sure as I have not seen photos of high end cars restored to that level mainly just original examples to date. Perhaps if I saw some restored examples for comparison I would use that as a reference.

The challenge with showing a restored car or section of a car is that one (given our focus here) would need to point out the short comings when found and owners would not take that kindly. One of the issues magazines had over the decades which lead to many an owner to simply copy ever detail - correct or not. Also standards, expectations and knowledge has progressed over time.

[RoyceP]

If that is the case then the NOS springs are just not going to be correct looking without at least as much effort as it would take to make the Eaton Detroit springs look the part. As has been mentioned before the assembly line springs had a part number roll stamped in the short leaf and they also had paint stripes for quick identification on the line.

Where are the originals that came off your car? They should have traces of the paint stripe and also the original roll stamping on the short leaf. If you have those you can at least know what you have to do.

Agreed Bob. So far my understanding is that the only stamp on the NOS set is the paint stamp in yellow on the top of the spring and no actual steel stamp marking on the bottom leaf. I am not sure if the Eaton or the Scott Drake leafs are the most accurate as I have only received photos from Scott Drake. However if they look good and are my best option I will go that route and hope to find a bottom spring with a good stamp at some point. Hopefully once stripped and treated they at the very least will look correct. I have seen some guys running the paint stamp on the top of the spring like Scott Drake offers. Not sure if I would go that route or not, as it would mean that the part is a reproduction of an NOS part and not original. Perhaps it is a question of personal taste. I have seen the same thing done with sheet metal parts etc. My lower tail pan is an NOS replacement part, but I plan to paint red oxide primer over it so it would look fresh like the rust of the car.l Not even sure of the stencils are available or if you would have to make up your own. Do people even go to that level. I am not sure as I have not seen photos of high end cars restored to that level mainly just original examples to date. Perhaps if I saw some restored examples for comparison I would use that as a reference.

[bullitt68]

If that is the case then the NOS springs are just not going to be correct looking without at least as much effort as it would take to make the Eaton Detroit springs look the part. As has been mentioned before the assembly line springs had a part number roll stamped in the short leaf and they also had paint stripes for quick identification on the line.

Where are the originals that came off your car? They should have traces of the paint stripe and also the original roll stamping on the short leaf. If you have those you can at least know what you have to do.

Unfortunately the original leaf springs are long gone and the leafs on my car had major flat spots, no stampings, wrongs straps etc, I am looking to find more suitable replacements.

[Bob Gaines]

Agreed Bob. So far my understanding is that the only stamp on the NOS set is the paint stamp in yellow on the top of the spring and no actual steel stamp marking on the bottom leaf. I am not sure if the Eaton or the Scott Drake leafs are the most accurate as I have only received photos from Scott Drake. However if they look good and are my best option I will go that route and hope to find a bottom spring with a good stamp at some point. Hopefully once stripped and treated they at the very least will look correct. I have seen some guys running the paint stamp on the top of the spring like Scott Drake offers. Not sure if I would go that route or not, as it would mean that the part is a reproduction of an NOS part and not original. Perhaps it is a question of personal taste. I have seen the same thing done with sheet metal parts etc. My lower tail pan is an NOS replacement part, but I plan to paint red oxide primer over it so it would look fresh like the rust of the car.l Not even sure of the stencils are available or if you would have to make up your own. Do people even go to that level. I am not sure as I have not seen photos of high end cars restored to that level mainly just original examples to date. Perhaps if I saw some restored examples for comparison I would use that as a reference.

The service replacement spring sets were typically metal stamped with a engineering number on the bottom leaf besides the stencil. The NOS ones you are looking at must be some very late service replacement springs given the missing metal stamping.  FYI the stencil in this instance and context would not typically be on a original assemblyline car part. It is a sign in a negative way of a replacement part IMO. Springs like that are on par with a repro . I would be concerned what other missing details that set of springs might have .  They would not be worth any kind of a premium IMO. Hopefully you will feel better about opting to not bid on the NOS replacement set.

[J_Speegle]

As mentioned earlier service replacements/later NOS will often be stamped differently than factory - Example below

[bullitt68]

As mentioned earlier service replacements/later NOS will often be stamped differently than factory - Example below

Thanks Jeff just confirming those are factory replacement and not factory installed original stamoing

[J_Speegle]

Thanks Jeff just confirming those are factory replacement and not factory installed original stamping

Yes

Here are some examples of stampings from assembly line rear springs. Couple of them were lose springs the lower left is one identified as coming from a 68 San Jose Mustang. One supplier (the upper tight identified as coming from a 68 NJ car) stamped them cross wise to the length of the leaf)

[bullitt68]

Yes

Here are some examples of stampings from assembly line rear springs. Couple of them were lose springs the lower left is one identified as coming from a 68 San Jose Mustang. One supplier (the upper tight identified as coming from a 68 NJ car) stamped them cross wise to the length of the leaf)

Great stamps. Thanks Jeff. Now I know what I am looking for. The hunt continues

[J_Speegle]

This should be one of the possible springs you'll be looking for - C7ZA-5556-AS

Often what was installed but it depends on what options your car came with in addition to being a very late GT 390 4 speed fastback. Things like AC and PS often are part of the differences. Picture is also from a San Jose built (and supplier) example