Formula S (HD) Leaf Springs

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The A-Body Guy

The A-Body Guy

The A-Body Guy
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Hello -

Does anyone know how many different leaf springs were used on Formula S (HD) cars from 1967-1969 and or if certain part numbers are better / worse?

I recently found out about at least two:

1967 - Six leaves both sides. Galvanized inter-liners. Both have the same last three digits 056.

1968 - Six leaves both sides. Plastic inter-liners. Both have the same last three digits 132.

I physically have both of these and they appear identical on the cars. My guess is ‘Ma MOPAR’ wanted to save money, switched to plastic and changed the part number.

Thanks in advance.

PMW
 
I don't know that those stamped numbers correspond to the part numbers, because those don't match anything in my reference. The following are all 6 leaf "HD" springs.

2808 607 - 1967 - HD except 383
2808 677 - 1967,68,69 - 383 (all)
3004 588 - 1968,69 - HD except 383
3420 183 - 70-72 - HD 2dr
3420 184 - 70-72 - HD 4dr
3549 945 - 1973 - HD
3722 293 - 1974 - HD 2dr
3722 294 - 1974 - HD 4dr
 
Here is a section from the build sheet … I know the 892 & 893 are correct ‘build codes) for heavy duty (340 / 383) formula s cars.

The leaf spring code is 056 on the ‘67 & 132 on the ‘68.

I apologize these would be build ‘codes’ not ‘part numbers’.
 
C36733C6-2699-47F7-BFB4-06ED0DCD3F73.jpeg
 
My 67 fastback with HD suspension package (NOT Formula S) shows 893/892 for the torsion bars, and 072 for the leaf springs.

Note that replacement springs may or may not have the same number of leafs — you can get the same spring rate with fewer, heavier leafs or with more, thinner leafs.
 
The A-Body Guy said:
Here is a section from the build sheet … I know the 892 & 893 are correct ‘build codes) for heavy duty (340 / 383) formula s cars.

The leaf spring code is 056 on the ‘67 & 132 on the ‘68.

I apologize these would be build ‘codes’ not ‘part numbers’.
Click to expand...
I believe that those #'s are corresponding with the part #'s. Meaning the few digits on the build sheet are usually the last few numbers of the part number . I'm sure if I'm mistaken I will be reprimanded. Lol
 
This is from the 69 Factory Service Manual (67 Was the same, assume 68 would be as well, didn't check)
springs69.jpg



Alan
 
Bennoel 10 said:
I believe that those #'s are corresponding with the part #'s. Meaning the few digits on the build sheet are usually the last few numbers of the part number . I'm sure if I'm mistaken I will be reprimanded. Lol
Click to expand...
No, those numbers don't seem to have any relation to the part numbers. I posted the part numbers in Post #2. "067" and "072" do not appear in any of the part numbers in the list.
 
This is a 69 340 4spd swinger, can only see the left leaf spring. I'll try and get a pic of the spring in the next day or so. Looks like "64" ???

20241117_134813.jpg
 
Rad says "66" which is the last digits for a correct 340 69 a body rad and the torsion bars are 892 and 893 which i also believe are for a 340 a body. Just my observation maybe not correct???
 
mvh said:
My 67 fastback with HD suspension package (NOT Formula S) shows 893/892 for the torsion bars, and 072 for the leaf springs.

Note that replacement springs may or may not have the same number of leafs — you can get the same spring rate with fewer, heavier leafs or with more, thinner leafs.
Click to expand...
This is partially the reason for the post. I was under the impression the HD bars and springs were based on the Formula S package.

My 68 is a /6 AC car which I read here also got the HD suspension … that got me wondering about springs as I believe T-bars are engine based.

It ‘appears’ /6 A/C got HD all the way around even with the 7 1/4 readend.

Without A/C the T-Bars are significantly smaller (drag race bars).

Learn something new everyday.

PMW
 
The A-Body Guy said:
This is partially the reason for the post. I was under the impression the HD bars and springs were based on the Formula S package.

My 68 is a /6 AC car which I read here also got the HD suspension … that got me wondering about springs as I believe T-bars are engine based.

It ‘appears’ /6 A/C got HD all the way around even with the 7 1/4 readend.

Without A/C the T-Bars are significantly smaller (drag race bars).

Learn something new everyday.

PMW
Click to expand...
Yes I believe if you ordered from the factory a/c the vehicle would come with the 340 torsion bars and even the 5.5" wide steel wheels, even if only a /6 engine.
 
The A-Body Guy said:
This is partially the reason for the post. I was under the impression the HD bars and springs were based on the Formula S package.

My 68 is a /6 AC car which I read here also got the HD suspension … that got me wondering about springs as I believe T-bars are engine based.

It ‘appears’ /6 A/C got HD all the way around even with the 7 1/4 readend.

Without A/C the T-Bars are significantly smaller (drag race bars).

Learn something new everyday.

PMW
Click to expand...
No, that is not correct. HD suspension was its own option checkbox. Yes, it was included in the Formula S package, but a customer could order it with any engine option. Slant six taxis (Darts and Valiants) often got the HD suspension. And with the trailer towing package, as mentioned.

On my 67 Barracuda broadcast sheet, under "Fleet Items", there is box labeled "H.D. SUSP. WO SW. BAR" with the numeral "3" below it.
 
The A-Body Guy said:
Hello -

Does anyone know how many different leaf springs were used on Formula S (HD) cars from 1967-1969 and or if certain part numbers are better / worse?

I recently found out about at least two:

1967 - Six leaves both sides. Galvanized inter-liners. Both have the same last three digits 056.

1968 - Six leaves both sides. Plastic inter-liners. Both have the same last three digits 132.

I physically have both of these and they appear identical on the cars. My guess is ‘Ma MOPAR’ wanted to save money, switched to plastic and changed the part number.

Thanks in advance.

PMW
Click to expand...

I have 3 Formula S Fastback Barracudas. I've pulled the Numbers from the original rear springs.

1966 Formula S, 4 speed = 2403804 both sides

1967 Formula S, 4 speed = 2835024 both sides

1968 Formula S, Automatic = 2835056 both sides

I also have MOPAR replacement springs for a 71 340 Duster, 4 speed = 3722133 both sides
 
The A-Body Guy said:
... I know the 892 & 893 are correct ‘build codes) for heavy duty (340 / 383) formula s cars...
Click to expand...

383 torsion bars and front sway bar are thicker on "68" 383 Formula S Barracudas than 340 Formula S Barracudas.

.89 diameter torsion bars and .94 front sway bar on my 68 Formula S automatic Barracuda.
 
Yes, big block cars got different springs and t-bars. I have never seen anything that indicated that they got a different sway bar, though. My source shows all 67-69 A-bodies as .88 (7/8 inch).
 
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