SAAC Forum

The Cars => 1968 Shelby GT350/500/500KR => Topic started by: TXShelbyman on October 29, 2021, 12:37:00 PM

Title: Leaf Spring Question
Post by: TXShelbyman on October 29, 2021, 12:37:00 PM
My 68 GT500 has a build date of 2/20/68. It is an automatic with air. The rear springs are marked C7ZA 5556 AR 7BT.

I noticed when dissembling that they are 5 leaf and have 67 type clamps ( I guess they are 67 type as they are 2 piece). One of the leaves runs almost the entire length of the base spring. Are these the correct springs? If they are, do they make a replacement anti-squeak pad for the long spring as it is square with a nub on the back. Thanks!
Title: Re: Leaf Spring Question
Post by: TXShelbyman on October 29, 2021, 01:13:19 PM
I think I may have answered my own question. According to the Ford books the C7ZA AR spring was a 4 leaf. Looks like someone added a helper spring for some reason. The next question is since the original clamps are gone with the 2/20 build date should they be square hole or round hole and in the bigger picture, does it really matter?
Title: Re: Leaf Spring Question
Post by: Bob Gaines on October 29, 2021, 01:31:43 PM
Quote from: TXShelbyman on October 29, 2021, 01:13:19 PM
I think I may have answered my own question. According to the Ford books the C7ZA AR spring was a 4 leaf. Looks like someone added a helper spring for some reason. The next question is since the original clamps are gone with the 2/20 build date should they be square hole or round hole and in the bigger picture, does it really matter?
It isnormal for a Mustang/Shelby to sit lower in the back then the front from the factory. With that said owners liked the forward rack of higher in the back which cause some to make changes like to add leaves to help raise the car up in the back The dated springs seem a little early for a 68. The AR springs were used on both 67 and 68 production Shelby's
Title: Re: Leaf Spring Question
Post by: shelbydoug on October 29, 2021, 02:44:28 PM
Quote from: Bob Gaines on October 29, 2021, 01:31:43 PM
Quote from: TXShelbyman on October 29, 2021, 01:13:19 PM
I think I may have answered my own question. According to the Ford books the C7ZA AR spring was a 4 leaf. Looks like someone added a helper spring for some reason. The next question is since the original clamps are gone with the 2/20 build date should they be square hole or round hole and in the bigger picture, does it really matter?
It isnormal for a Mustang/Shelby to sit lower in the back then the front from the factory. With that said owners liked the forward rack of higher in the back which cause some to make changes like to add leaves to help raise the car up in the back The dated springs seem a little early for a 68. The AR springs were used on both 67 and 68 production Shelby's

Yes this is true. You are speaking of completely stock, as delivered. However, if you notice many (if not all) vintage pictures of R models will show an additional top spring.

Not only does this change the posture of the car but by doing so it improves the cornering capability of the front suspension and improves dramatically the stock harsh bottoming out of the rear axle housing.

So it isn't some sort of a berserk mindless change, there is good reason for it. As Bob says, they didn't come that way new. They all sat down in the back since that is the "Competition" rear spring design from Ford.
Title: Re: Leaf Spring Question
Post by: KR500 on October 29, 2021, 05:52:50 PM
Quote from: TXShelbyman on October 29, 2021, 01:13:19 PM
I think I may have answered my own question. According to the Ford books the C7ZA AR spring was a 4 leaf. Looks like someone added a helper spring for some reason. The next question is since the original clamps are gone with the 2/20 build date should they be square hole or round hole and in the bigger picture, does it really matter?
The most common leaf spring band clamp on a 68 Shelby/Mustang would be a square hole clamp ( I have seen 2 version of the square hole clamp). Most common on 65-67 are round hole clamps but square and D shaped hole clamps  are possible on all years ( 65-69 ). All 65-70 Shelby/Mustangs use a 4 leaf leaf spring from the factory.

Rodney