Rear suspension upgrade

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Jul 6, 2015
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My Car
1973 Mustang Grande 351C 2v
I am in the process of upgrading my rear suspension. I am installing a set of grab-a-trak 4.5 leaf springs with reverse eye (removing my 1” drop blocks) as well as a set of cal-tracks. I was planning on just using the stock rear shackles and some urethane bushings. I had been doing some research and saw some comments that I should not install a stock style bushing at the shackle when running the solid bushing up front that come with the cal-tracks. I found these and wanted some opinions if anyone has experience with this set up.

I am basically trying to eliminate my lowering blocks, correct a bad wheel hop issue as well as a lack of traction issue.

My .02 cents save the coin and stay with the stock shackles. I am running calvert springs and caltracs with stock shackles. Just run a good rear shock, I am running QA1s.

I am using the Maier Racing 4.5 leaf springs with Bilstein shocks and I am very happy with this setup. The suspension is firm but comfortable and the traction is amazing. With nearly 500hp and a Truetrac the traction is excellent when stepping on the gas. I am using a polyurethane bushing on front and normal rubber bushings at the shackle. Go to his website and read about it. They are expensive but with this setup you dont need Caltracs.

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Depending on how serious you want to get with the bushings here is what we use to do.

I made aluminum bushings with a thin UHMW Ultra High Molecular Weight Polyethylene bushing next to the bolt to prevent squeak. I was a tool & die maker so easy for me to make them. Would also put the front half of main leaf spring on top going under the axle housing but not past the mount. Then made clamps to clamp the springs tight together. It for sure stopped wheel hop and improved handling for next to no cost.