Topic: Spring color question 10/68 SJ 390 4 speed GT Sports roof

[willy001]

Ready to paint the front springs and I'm not sure if the springs I took off are original. I don't want to duplicate without some verification.
69 sports roof, GT Equipment Group, 390, 4 speed, a/c, disc brake, SJ 10/24/68
Here's a picture of the springs when I removed them. It appears to me they are yellow and red.
Is this what I should expect?

Bill

[J_Speegle]

Don't have any matching buildsheets and wouldn't look to a replacement part MPC for guidance on colors, or part numbers with out some cross confirmation

390's are not often seen compared to others- then add in you've got a San Jose car

I have no reason to believe they are not original to the car - don't know the history of the car, do you?   

If I suspected that they had been changed I did find springs with those markings being used originally on a 69 F code AC , PS equipped deluxe interior sports roof with standard suspension. Doesn't seem that that cars weight and options would be the same as you set up

Sorry can't be of direct help on this one

[willy001]

I know where the car has been the last 20 years or so but before that I have no clue.

When I disassembled the front of the car it appeared to be original. There was a ball joint change somewhere along the way but other than that the upper and lower arms appear original. I don't have any compelling evidence that the springs are not original but I can't be 100% certain. Haven't decided how to proceed yet but thanks for the reply and input.

[WT8095]

I found information on some other possibilities for the springs you have. Keep Jeff’s statement in mind: a replacement parts listing is not gospel and should be corroborated with another source. With that in mind, hopefully the following information will aid you in your research.

Per the ’75 MPC:

Possible matching paint codes:
#92 C6AZ-B: 1 Red & 1 Yellow - Load 1875, Coils 10-1/2, Wire Dia .628, Free Length 19-1/8
#96 C6AZ-F (r/b C6AZ-E(95)): 1 Orange & 1 Yellow - Load 2200, Coils 10-1/4, Wire Dia .666, Free Length 18-5/8
#4S C7ZZ-AG: 1 Orange & 1 Yellow - Load 1580, Coils 8-3/4, Wire Dia .625, Free Length 15
#4V C7ZZ-AN: 1 Red & 1 Yellow - Load 1520, Coils 9-1/2, Wire Dia .600, Free Length 16-1/4


69 GT w/390 4s AC PS after 9/11/68 (your car as described)
#4P C7ZZ-AE (r/b C7ZZ-AD(4N)): 1 Gold & 1 Yellow - Load 1740, Coils 9, Wire Dia .635, Free Length 15-1/2

69 w/390 4s AC PS Standard susp. (comparing to standard suspension with your options)
#4U  C7ZZ-AK: 1 Gold & 1 Violet - Load 1720, Coils 9-1/2, Wire Dia .610, Free Length 16-5/8

I couldn’t tell if the left paint mark was red or orange, so I looked up both. I don’t see any use of the 92 & 96 springs on Mustang, Fairlane or fullsize for 1969. You have to go back at least to 1968 to find any reference, and that’s on a fullsize. Plus, those springs are about 2-4 inches longer than Mustang springs, so I don’t think you have either of those. The 4S springs are listed for a number of GT combinations for 250, 302 & 351 cars, but no 390s. The 4V springs are listed for some combinations of 250 & 302 w/standard suspension, but also no big blocks. The application Jeff listed is among the lilst that used the 4V. I suspect you may have 4S or 4V, which according to this source is not what was supposed to have been on your car. I should ask: is the 390 the original engine?

Can you list the measurements of your springs? Number of coils, wire diameter, and free length.

[willy001]

Yes the car is an "S" code car with the GT suspension package.

The springs I took off measure 9-1/2 coils, 16-1/2 free length and .600 wire dia.
This matches up well with the #4V C7ZZ-AN springs you listed that are red and yellow.

Hummmm....

[J_Speegle]

Yes the car is an "S" code car with the GT suspension package.

The springs I took off measure 9-1/2 coils, 16-1/2 free length and .600 wire dia.
This matches up well with the #4V C7ZZ-AN springs you listed that are red and yellow.

Yes it should match the MPC the question is if its the original marks. The MPC only lists the replacement part so if the springs were replaced the Red Yellow marked ones would have been the replacements 6 years later. 

Believe that still leaves  you with the question what was installed originally. The Gold and Yellow markings match the buildsheet I have

[willy001]

So Jeff,
From a judges point of view gold and yellow is what you would expect based on what we know today?

[J_Speegle]

So Jeff,
From a judges point of view gold and yellow is what you would expect based on what we know today?

With my Judges hat on I would suggest that your not likely going to find a judge at the show that will have built a 69 non- Mach sportroof equipped like yours. Because of that a judge would likely not question the markings on your springs as they might on other markings found around the car (possibly). If asked you have a reason for either choosing the spring marks as found or with a car with similar equipment. Neither is without a possibility of being found incorrect.

With my owner's hat on I might make the choice to reproduce them or to leave them off if I was questioning the correctness. If they are not correct and another owner sees and copies the marking then IMHO I'm responsible for that car possibly getting deducted for the marks at some point. You can always add them later if more supporting or correct information becomes available. Changing the stripes isn't an easy task once installed



Consider that the paint markings are not required and can only loose you points and something that one often focuses on after all the needed details are addressed and corrected.

IMHO way too many cars getting no trophy or Bronzes with paint marks all over the place.

[WT8095]

Yes it should match the MPC the question is if its the original marks. The MPC only lists the replacement part so if the springs were replaced the Red Yellow marked ones would have been the replacements 6 years later. 

Believe that still leaves  you with the question what was installed originally. The Gold and Yellow markings match the buildsheet I have

My post may have been misleading the way I spaced the entries. The first four codes were possible matches for the paint marks on Bill's springs. The fitfth entry, C7ZZ-AE (1 gold 1 yellow) is in fact what the '75 MPC lists as replacement for Bill's application. That doesn't confirm what was on his car originally - only what would have been the Ford recommended replacement. (Which was replaced by C7ZZ-AD; I did not list the specs for that spring but I will update my post later.) The sixth entry was for comparison to a standard suspension, showing the load rating was only 20 lbs less, not ~200 lbs as would be the case with either the red/yellow or orange/yellow springs.

Per the MPC, both the AG and AN were rated about 200 lbs lighter than the recommended replacement. It doesn't appear they would have been correct either from the factory or as replacement. Granted this is mostly based on the MPC, but now you have referenced a build sheet which adds support to the hypothesis.

I also should have explained what the "4S" "4V" etc. codes are for folks who don't have access to an MPC. The first part of the spring section has a table with all of the spring specifications - part number, load rating, wire diameter, etc. The other section lists the applications. It is a huge, complicated table spanning dozens of pages. The application table used the spring code numbers like "4V" because there isn't room to squeeze an entire part number into the individual boxes. So Bill, for your car you turn to the 1969 subsection, find the Mustang pages, then narrow down to heavy duty suspension (since it's a GT), find the lines for 390, narrow down to the single line for build date AFTER 9/11/68, then start going across the columns. There is a column group for each type of transmission, and within that group of four columns you pick the one with the combo for both A/C & P/S. That box says "4P". Phew! It probably would have been a lot easier to post some scans of the tables... 

[WT8095]

So Jeff,
From a judges point of view gold and yellow is what you would expect based on what we know today?

Leaving the judging aspect aside (which Jeff addressed nicely in his reply), you still need to determine mechanically what springs should be on your car. Per the evidence we currently have, your springs should be some 200 lb higher rating than the ones you have. Ignoring the paint marks, your measurements indicate a spring with around 1500 lb rating. That's a lot lower than even the standard suspension rating of 1720 lb. I would think that would have a noticeable impact on handling. (Load rating and spring rate are not exactly the same thing of course.)