I tried to obtain a good set of rear shocks for the Cobra, and IPS came through with HAL adjustable shocks and brackets to adapt the double eye shocks to the Cobra mounts.  These mounts will allow addition of Coil-overs later if I want.  Here is what they look like on the car:

Left Wide

Upright -1

Lower right from top

Lower Right

Note--on December 21, a few weeks after installing the KB springs, I noticed that the left rear shock had started rattling.  I checked the schocks, and found that the noisy shock only had 1-1/2" travel left after lowering the car with the KB springs.  I remember bottoming out the left shock really hard on the street once.  This damaged the lower Heim joint (spherical bearing) on the left HAL shock.  I obtained replacement lower bearings from Hal and changed out both sides; this cured the noise.  While I had the shocks out, I changed the spacer arrangement at the top mount to get more compression travel in the shocks.   There is a 1" spacer above the bracket on upper shock mount that IPS says to move when using lowering springs to get the travel right on the shock.  I took this spacer out and put it on the trunk side of the mount as a big washer to take up some bolt thread length so I could use the original IPS bolt.

When I removed the shocks temporarily to change out the Heim joints, I took some additional pictures that more clearly show the IPS/HAL setup.

The 1" long spacer in the second picture is not used between the bracket and the body when lowering springs are installed.  The washer has a shoulder which centers the bolt in the body hole where the original shocks have a large rubber bushing.

The lower mount straddles the lower control arm and uses the stock shock bolt and nut.  You don't need the Ford hardened washer between the shock and the control arm when installing the IPS brackets.  (Not shown in any pictures.)  There are two dimensions which are critical to the fit of the lower bracket:

1.  I had to grind some aluminum off the top side of the control arm to allow the bracket to come down low enough to get the bolt in.  IPS should change the dimension by about 1/16" on later brackets to correct this problem.  The aluminum lower control arm on the car is cast, and the clearance between the bottom of this bracket and the top case surface of the arm may vary some from car to car.
 
 
 
 

2.  The hole through the lower bracket for the stock 14mm shock bolt must be 9/16" diameter as shown in the picture on the left.  Mine was too small for the 14mm bolt, and I had to drill it out using a drill press.  IPS should correct this on later kits.  Make sure to check yours when you get them.

I have driven the car several months with the spherical bearings at both ends of the shock.  With this arrangement, there is metal to metal all the way front he wheel bearing to the chassis with no rubber for noise isolation.  The additional NVH didn't bother me much, but it may bother passengers.  I decided to install some optional urethane bushings in the lower shock mounts.  These were obtained from Hal and the IPS bracket width dimension of 1.5" is perfect for these softer bushings.  They can only be installed in the lower mount, however, because they will only work if the mounting bolt is perfectly perpendicular to the shock body.  The upper mount has some angle to it.

At left is what the soft bushing looks like installed on the right shock lower mount.  That is a half-shaft to the right of the shock mount.

First impression is that these bushings have eliminated much of the NVH associated with the original installation, but I need to drive them some to see for sure.  They certainly did not hurt the wheel hop control!!
 
These shocks have an adjustment range setting of 1 to 12, with 1 being the softest.  Currently, I run these shocks set at 4 on the street with the KB springs.  At 4, there is a little wheel hop on a hard start.  At 6, the hop is pretty much gone with the KB springs.  At 8 or 9, there is almost no movement in the rear end.  I have autocrossed successfully with the shocks at 6, with stock springs, and drag raced with them at 12, with the stock springs, but still had some hop on a slick strip.

I have concluded that you must install both springs and shocks to control the wheel hop on a 99 Cobra.  Shocks alone won't do it; I tried it.  Springs alone won't do it; I've tried, by setting these shocks loose with the KB springs.  Plan on buying springs and shocks for the rear of a 99 Cobra if you are going to do any hard starts from a stand-still!  I like the KB and IPS/Hal combination, but others may work.  The shock will need to be very stiff, however, and I have not done any testing of other options.

I have not been on a drag strip yet with the KB springs and these shocks in the current configuration.  Informal testing of the country road type says these shocks and KB springs will be great for wheel hop control on a 99 Cobra.

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