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Discussion Starter #1
Was thinking on ordering a set of the stainless rear shackle kits for my car. Scott Drake shows three different kits. The RSK13, RSK14, and RSK15.

The RSK13 kit is described for 65-73 cars, while the RSK14 is described for same years w/dual exhaust, and the RSK15 is for "extended dual exhaust". Did Ford make different shackle arm lengths for dual exhaust cars for clearance or? From the photos, the RSK15 looks a little longer than the other two?

 

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for what it's worth, NPD listed the same type of variations (but not stainless). I have a set (non-stainless finish).

The greyish finish was nice, but they were made of a thinner metal than my originals. I wonder if those are made by the same manufacturer in stainless or if the ones i have are actually stainless but powder coated or painted?

needless to say, i'm not using them.
 

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thats part of the reason why i am not using them either. i am using the extended shackles that were on the car from the 70s. they are 1/4th inch thick plate steel.
 

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thats part of the reason why i am not using them either. i am using the extended shackles that were on the car from the 70s. they are 1/4th inch thick plate steel.

Aftermarket long shackles are a band aid fix to saggy leaf springs. You are not going to break a stock shackle. I'm making 550hp-600hp with a 5 speed transmission on stock shackles in my Mustang. I used to drag race the 70 Mustang in my avatar picture with drag slicks, 4.56 gears, 4,000 stall converter behind a mild 351C on nitrous with the original spring shackles. Never bent or broke one.

Where a thicker shackle might make a difference is during cornering. Not as much deflection. And that includes using upgraded bushings. I have a set of Global West Del A Lum shackles and bushings waiting to be installed. Your shackles might be 1/4" steel, but they are longer, have multiple holes drilled in them weakening them, and will flex greatly when deflected due to their long length.

Del A Lum


 

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no the car has brand new springs in it i just like the 70s lifted rear. and they only have one set of holes in them. my uncle made them himself and they only have the holes where they mount to the car and where they mount to the springs. and they dont bend at all.
 

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no the car has brand new springs in it i just like the 70s lifted rear. and they only have one set of holes in them. my uncle made them himself and they only have the holes where they mount to the car and where they mount to the springs. and they dont bend at all.
Something else the extended length shackles do is screw up the pinion angle, putting stress on the transmission, U-joints, and differential. The right way to fix a saggy rear is new springs.

IIRC, the double "L" looking shackles are"correct" for 65-69 Dual exhaust Mustangs, for the left side only. Stock shackles were 1/2", and not stainless.I have never heard of a stock shackle breaking while driving.
 

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well its had them on for the last 39 years i think if any problems were going to happen they would have happened in the 160,000 miles of driving.
 

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well its had them on for the last 39 years i think if any problems were going to happen they would have happened in the 160,000 miles of driving.
How long are they?
 

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Discussion Starter #9
I went ahead and got a set of these with the 15% of sale at CJ. A bit more bling than I thought but they will be covered up. They are only 010-020 thinner than the originals. They almost look nickel plated.
 

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they are 3 inches longer than stock roughly. they give the car the perfect stance in my opinion.
Better check the pinion angle. Sounds to me like your rear springs are almost flat.
 
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