Mustang 1 inch Rear Lowering Block Kit (1965-1966) Installation Instructions

Tools Required:
  • Jack Stands and Jack
  • Wheel Shocks
  • 9/16 inch Deep Socket
  • 11/16 inch Deep Socket
Install Difficulty:
  • Moderate
  • Moderate Project
Mustang 1 inch Rear Lowering Block Kit Install Image
Mustang 1 inch Rear Lowering Block Kit Install Image
1. To start installing your new Mustang 1 inch Rear Lowering Block Kit, you need to elevate the rear wheels, so it is vital to chock both of the front wheels to prevent the car from moving during the project.
Mustang 1 inch Rear Lowering Block Kit Install Image
2. Place a floor jack under the Mustang differential and lift the rear until both rear tires are about 6 inches off of the ground. Place jack stands under the “rails” formed by the unibody. Then, slowly lower the car onto the jacks, and continue lowering the floor jack until most of the tension is released from the leaf springs (the tires should still be 1-2 inches off of the ground).
Mustang 1 inch Rear Lowering Block Kit Install Image
3. Use a 9/16 inch deep socket to remove the nut holding the bottom of the shock to the spring plate. Using an 11/16 inch deep socket, remove the four nuts holding the leaf spring plate. CAUTION: The axle housing will likely move as the last bolt is removed. To reduce the amount and force of that movement, adjust the floor jack to remove most of the tension from the Mustang springs.
Mustang 1 inch Rear Lowering Block Kit Install Image
4. Repeat on the other side. CAUTION: Once both sides of the axle housing have been disconnected, the axle housing will be supported solely by the floor jack and the Mustang drive shaft (so make sure it is relatively balanced).
5. Adjust the floor jack to produce a gap between the axle housing and the Mustang leaf spring. Install the lowering block in the gap. Ensure the “post” side of the block is up (there is a circular raised tab on the top of the spring which fits into a circular cavity on the bottom of the block, and a circular raised tab on the top of the block which fits into the recessed area on the bottom of the axle housing).
Mustang 1 inch Rear Lowering Block Kit Install Image
6. Reattach the Mustang shock to the leaf spring plate, then reattach the spring plate using the supplied U-Bolts and 11/16 inch nuts. Ensure that the hole in the spring plate is centered over the tab on the bottom of the spring, and the lowering block is centered between the spring and axle housing mount. CAUTION: Be careful to avoid bending, stressing, or pinching the brake lines while installing the U-Bolts.
Mustang 1 inch Rear Lowering Block Kit Install Image
7. Repeat on the other side, ensuring that the axle is centered side to side before final tightening (do not over-tighten nuts on U-Bolts). If the axle is not centered (the distance from the Mustang springs to the backing plate of each wheel should be equivalent), loosen the first side and adjust as necessary.
Mustang 1 inch Rear Lowering Block Kit Install Image
8. Once all of the bolts are tightened, use the floor jack to raise the body off of the jack stands. Remove the jack stands and lower the car to the ground. Measure the new ride height and enjoy your new Mustang 1 inch Rear Lowering Block Kit!
Mustang 1 inch Rear Lowering Block Kit Install Image