Saturday, January 20, 2018
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Lowered Expectations

The Mustang in Black car has had two inches removed from the IRS subframe but rides at a stock ride height. This improves the suspension geometry and increases road clearance.

When we first introduced our IRS kits we intended them to be designed to install the system with a minimum of modifications to both the car and the IRS unit. The unit works and looks great, but we knew there would be those who would like a little more lay down in the stance of the car.

70 Mustang with the standard ride height. Although it's level, the trend is to lower the stance from the original Ford settings.

Lowered IRS Units

Dave Stribling Restorations now has a program for those IRS users who want to have a lower stance for their vintage ride. The IRS in base form sits level, but the lowered kit allows for up to 2 inches lower stance while adding road clearance and adding to the travel of the suspension.

Standard Ride Height Comparisons

With 245/45-17 tires
With taller 255/50-17 tires

Dave Stribling Restorations has developed a special jig that allows the removal of about 2 inches of material from the IRS subframe - and keeps the mount points in the same location. By keeping the mount and alignment points the same the system will work as a direct bolt-in for the current mounting kit.

Photo on the right shows the "standard" ride height using the lowered subframe. Improved suspension travel and an additional 1.75 inches of ground clearance.


The photo on the left shows the cradle down a full two inches - about 3/4 of an inch to spare!

Road clearance is gained by changing the angle of the front mount to near horizontal. The mounts are flat and not angling up towards the chassis. Road clearance can be improved up to two inches! By raising the subframe in the chassis, the suspension travel is also improved.

The lowered system consists of the following items:

  1. Lowered subframe unit
  2. Special lowered shocks
  3. Optional spring rates if necessary

Lowered IRS Notes:

Ground Clearance - With the non-altered cradle the ride height is about 3.75 inches. With the lowered unit, the ground clearance is much better, with about 5 inches for the standard and 4 inches at the maximum lowered height.

Considerations For Using The Lowered IRS Cradle (at it's maximum lowered height)
Click here for more information about the
IRS Subframe Cradle Drop

If you would like to consider the lowered unit, you need to consider the following:

  1. You'll have to cut out the entire axle snubber assemblies. They will interfere with the travel of the upper control arm.
  2. For some applications you will have to dimple or modify the trunk area to make clearance for the swing of the upper control arm.
  3. This will require a special shorter shock absorber. This is a no cost option when purchasing the lowered unit with the IRS install kit. Exchanges may be available - contact us for more information..
  4. With some shock combinations you may be required to run a 7 inch spring. Call or e-mail for more information. Optional springs may add to the cost of the IRS install kit.
  5. You have less than one finger's worth of travel between the lip of the wheel well and the tire. Radiusing the wheel lip opening is highly recommended.
  6. Remember 245s will drop the car even farther. 245/45s are standard equipment on late model Cobras/ Mustangs.

Please contact us for any further questions on the lowered IRS units.