Shackle Mount Help Needed

[Propwash]

Hey Gent's,

Got the new frame rails in my project and am moving on to the new shackle mounts from AMD. After roughly jigging up the new right side shackle mount to the frame rail with Vise Grips, I noticed that the housing for the shackle bolt/bushings sits 1/2" further back than the factory measurement.

Before I removed the old shackle mount, I used a Plum Bob and centerd in the middle of the bolt/bushing housing and marked the location on the garage floor. All other dimentions of the new shackle mount line up pretty well except this area. With the plum bob set up on the new shackle mount measuring in that area, I am 1/2" too far back on my measurment on the floor.

If I move the whole assembly forward 1/2" to accomodate the offset, the rear of the shackle mount will be too far forward to be able to have a flush mate to the rear crossmember. Also, the top edges will not follow the same curve of the frame rail, making the trunk pan not fit well.

My questions are, can I mount this shackle mount in with the measurement being 1/2" further back than stock? Will the shackles pivot enough to be able to bolt in the leaf springs? If they still will bolt in, will this effect the ride height? Do i need longer shackles?

Any help would be much appreciated...

 

[72 Charger SE]

Did some reading from the Mopar Chassis Book on this one since it's been about 10 years and my memory isn't always as accurate as it used to be (dammit! age just creeps up and finds new ways to screw with you.)

Anyway, here's what I came up with. As long as your rear shackle is either vertical or with the lower (spring end) end slightly further back than the top of the shackle when you install your springs and rear axle, you should be fine.

Guessing that the 1/2 inch difference is built into the new mount to move upper mounting point further forward, to reduce problems for those cars where the upper mount was behind the spring end of the shackle.

 

[Propwash]

God Bless you man!!!! You have no idea how much that helps me out! Very much appreciated 72'.. Wonder if stock shackles would still slide in?

 

[72 Charger SE]

Hey, I'm learning this stuff as I go along too...even though I already knew that one before. So I get to learn things all over again! Just wanted to make that what I remembered was right. If it's not, then I guess I get to add learning to read and comprehend to the list of things to do that I used to know...

Anyway, glad I could help in some small way.

 

[detmatt1]

Good info, love this site!. I would still put a call in to AMD.

 

[snakeoil24]

1/2 difference sounds like the mount difference for 67 coronet