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

[bullitt68]

The bottom plate has squared off ends instead of rounded like the rest of the leafs in the set. You can grind them round to match or use the bottom leaf of the old set as discussed.

The other option I have considered is using the top leaf that is in great shape that came on my car. I will experiment with some of the various processes suggested and see if any look like a reasonable solution. If not back to the drawing board and I will just order up a set of leafs from Virgina Classic Mustang and call it a day. Regardless I do know that I am using the bottom leaf and need to see how well I can get that to look and if painting is my only option or not. That will provide the answer I need indeed

[J_Speegle]

Ok thanks. Odd that just the bottom leaf is squared off and the other leafs are rounded. The original leafs looks like they were cut by hand as they are quite rough and uncemetrical

Sorry can't recall - did we ever confirm that your rear leaf springs were original or could be to your car and application?

[bullitt68]

Sorry can't recall - did we ever confirm that your rear leaf springs were original or could be to your car and application?

Hi Jeff. The leaf springs that came in my car were not original units, they we replaced at some point, but I figured that it would be hard to tell the top springs apart, at least I didn't see any major differences between the ones that came on my car and the 50,000 mile original springs from my buddy's car. The top leafs (all the leafs) that came in my car are in perfect shape compared to the original ones from my buddies car. Perhaps I was wrong in assuming I could match the 2 sets together. I just figured that if I was to order a set of aftermarket ones and I have the bottom spring from the 50,000 mile car and the top spring from my car, that I would be ordering a set of reproduction springs for just 2 leafs. Perhaps I am over thinking this. I just want to get some springs on my car that look right, fit right that I will be happy with. It is shame that the original springs are so pitted, but what can I do other than sand the pits out.

[bullitt68]

I managed to clean up the correct bottom leaf as best I could without sanding away the part number. I don't think they will look that great if I just treat them as they still have some pitting. The other option is to use high build primer and sand the entire original set. I will experiment with the lower spring and see how it looks.  I will try the graphite and see if it looks good as I found that was the best option when I tested some various finishes previously. If that does not work I will order a new set of springs from Virginia Classic Mustangs and call it a day

[J_Speegle]

IMO there should be some texture - just no rust pitting - from the heating and quenching process. You can often see, for lack of a better term, "plates" - flat sections with rough outlines on many of the surfaces. Just don't over do it or they might come out looking like they were dipped in plastic or plastic coated like some exterior paint jobs 

Good luck with the attempt - this is when we find out what can work and what doesn't. Just part of the learning process so thanks for sharing 

[bullitt68]

IMO there should be some texture - just no rust pitting - from the heating and quenching process. You can often see, for lack of a better term, "plates" - flat sections with rough outlines on many of the surfaces. Just don't over do it or they might come out looking like they were dipped in plastic or plastic coated like some exterior paint jobs 

Good luck with the attempt - this is when we find out what can work and what doesn't. Just part of the learning process so thanks for sharing

Agreed thanks Jeff. I plan on doing a very rough dry spray with the graphite after the primer. May try burnishing it as well since it is not a paint product. Standby for results. Worse case scenario, I will go with Plan B. Which in some cases could actually be Plan A lol!

[bullitt68]

IMO there should be some texture - just no rust pitting - from the heating and quenching process. You can often see, for lack of a better term, "plates" - flat sections with rough outlines on many of the surfaces. Just don't over do it or they might come out looking like they were dipped in plastic or plastic coated like some exterior paint jobs 

Good luck with the attempt - this is when we find out what can work and what doesn't. Just part of the learning process so thanks for sharing

Hi Jeff. After cleaning up on of the bottom leafs I coated in with graphite and burnished it as well. It has a natural look to it. However what I have learned is that the graphite does not hide anything pitting like a paint product would. So I am going to attempt to paint the pitted springs and see what happens. I will try the Eastwood Phosphate rattle can paint after that and see how they look. If I am not happy with the result I will order a new set of leafs (painted of course) then disassemble them, strip them and coat them with the graphite and burnish them.

The first photo shows a bare metal leaf on the left beside the graphite leaf on the right. The next photo shows the Eastwood phosphate painted leaf on the right  next to the graphite leaf on the left

[J_Speegle]

The first photo shows a bare metal leaf on the left beside the graphite leaf on the right. The next photo shows the Eastwood phosphate painted leaf on the right  next to the graphite leaf on the left

Must be the lighting as on my screen there does not appear to be much difference and surely not dark like a heat treated quench part but as mentioned likely the lighting and the digital camera settings as well as other things.

One example




And another. Has been worked a little more on the right hand side of the picture



Not looking for an exact tone but one in a range that produces a noticeable contrast with the shackles, spring clamps and other bare steel parts in the same area

[bullitt68]

Must be the lighting as on my screen there does not appear to be much difference and surely not dark like a heat treated quench part but as mentioned likely the lighting and the digital camera settings as well as other things.

One example




And another. Has been worked a little more on the right hand side of the picture



Not looking for an exact tone but one in a range that produces a noticeable contrast with the shackles, spring clamps and other bare steel parts in the same area

Thanks Jeff. Yes it is the lighting. It is washing it out. I will try to take a better photo with less light. My understanding is that the shackles are phospated, the shock plates are a bare metal finish, the u bolt nuts are red dichromate, and the u bolts phosphate. I am leaning towards phophating the leafs at this point. I will most likely paint the badly pitted original leafs since I have come this far and try phosphating the smaller leafs to see how they turn out. Also leaning towards ordering a new set of leafs from Virginia Classic Mustang and stripping them and using which ever process ends up looking the most like the original heat treated quench approach. I will use the correct stamped original lower leaf and the new set combined. Hopefully the ride height with the new springs will be same as what I had previously

[J_Speegle]

..... My understanding is that the shackles are phospated, the shock plates are a bare metal finish, ................

I've not seen them phosphated originally.

To reproduce the original look some are phosphating then then tumbling or further dressing them to get to the right look. Guess we should be careful when describing what they should look like and how we're "faking" or reproducing the look. Might result in confusion or a non-correct final look. Same goes with many other parts where they were originally bare steel but the current practices of reproducing the look uses phosphating as one of the steps

Others opinions may differ

[bullitt68]

I've not seen them phosphated originally.

To reproduce the original look some are phosphating then then tumbling or further dressing them to get to the right look. Guess we should be careful when describing what they should look like and how we're "faking" or reproducing the look. Might result in confusion or a non-correct final look. Same goes with many other parts where they were originally bare steel but the current practices of reproducing the look uses phosphating as one of the steps

Others opinions may differ

Thanks Jeff. So what in your opinion would yield the correct look. Gun bluing for example. One thing I do find odd is that I am still able to order treated and unpainted leafs springs for other brands, but for some reason I have not been able to find leaf springs other than painted for my car. I am not sure what process the spring manufacturers are currently using to treat their respective springs, but it does have a dark phosphate look to it, which could be one of many different processes I would imagine. I am hoping that which ever process I use will offer some level of rust prevention as I live in a damp rainforest. I can literally see parts flash rust before my eyes. On the rear brake drums for example, I dry media blasted them and then used the vapour blasted to remove the dull flat texture and return it closer to what it would have been like when manufactured and literally within seconds you can see flash rusting occur due to the humidity in the air. So far phosphating has worked well for me in most applications as gave several other products for other parts and finishes. The only gun bluing I have used has been an involved process using heat and multiple applications. my understanding is that the heat draws the gun bluing into the pours of the metal and not only seals it, but also allows the product to go below the surface into the metal. Then I generally burnish with steel wool and Boeshield for rust prevention

Any advice would be greatly welcomed as alway

[bullitt68]

I've not seen them phosphated originally.

To reproduce the original look some are phosphating then then tumbling or further dressing them to get to the right look. Guess we should be careful when describing what they should look like and how we're "faking" or reproducing the look. Might result in confusion or a non-correct final look. Same goes with many other parts where they were originally bare steel but the current practices of reproducing the look uses phosphating as one of the steps

Others opinions may differ

Hi Jeff here is a better photo I hope of the of the leaf spring Phosphate paint vs Graphite

[bullitt68]

I found another set of local leaf springs. They have a different code/stamp, not sure if I am decoding the date correctly, but it looks like the Oct 27 and my car was built the 23rd week. I am not sure what AR stands for, or which plant is OE7. So far these new springs appear to be in better shape than the previous set of leafs I got from the same seller. I will hav a better idea once I strip the paint.

The other set I have are Nov 26, same plant AS

[Bob Gaines]

I found another set of local leaf springs. They have a different code/stamp, not sure if I am decoding the date correctly, but it looks like the Oct 27 and my car was built the 23rd week. I am not sure what AR stands for, or which plant is OE7. So far these new springs appear to be in better shape than the previous set of leafs I got from the same seller. I will hav a better idea once I strip the paint.

The other set I have are Nov 26, same plant AS

AR marked springs are for competition suspension. They are highly sort after.

[bullitt68]

AR marked springs are for competition suspension. They are highly sort after.

Really? Very interesting. What car would have received those springs. Would they have a different spring rating than the AS for example.