Mark Houlahan
Tech Editor, Mustang Monthly
February 1, 2000
Photos By: Tom Rounds

Step By Step

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The AGS 3 system includes Kenny Brown's Double-Cross subframe connectors, urethane bushing package, Koni struts and shocks, strut tower brace, lower crossmember brace, front lower springs, and a panhard bar kit with aluminum panhard bar. The Kenny Brown Jacking Rails, shown in the foreground, are not part of the AGS 3 system, but we decided to add these to the Modern Mach for its safety.
We visited Central Florida Motorsports, an up-and-coming Mustang and Ford performance parts outlet, for the work on the Modern Mach. We did not have the time or room in our shop to tackle the job ourselves, and CFM has installed several of Kenny Brown's AGS systems. Here, Kevin Kelly measures the ride height at all four corners and records the information on a notepad to check after the suspension is in place.
Kenny Brown's subframe design uses a welded-in cross brace that bolts to the rear hardware of the front seat, effectively cutting the free span between front and rear subframes in half. Kevin marks the areas on the subframes and the connectors for welding. These areas will need to be cleaned of all coatings and paint for a strong weld.
Carlos Navarro, owner of CFM, uses a D/A sander with 180-grit paper to clean and prep the subframes. If your Mustang has been undercoated, use a chemical stripper before sanding off any paint. After the subframes and connectors have been cleaned, they can be bolted to the seat bolts and aligned.
Kevin fires up the Miller MIG welder and places one-inch stitches along the inner and outer sides of the subframe connectors. A hand jack may be necessary to get the connector close enough to the subframe in some instances.
Moving to the back of the car, Kevin decides to tackle the toughest part of the job, the panhard bar. Kevin and Carlos work together to free the rear suspension. The rear shocks are unbolted from the axle housing first; then the coil springs can be pulled from the spring perches on the lower control arms.
The Kenny Brown panhard bar kit requires drilling out the axle housing brackets; thus the drum brake backing plates must be removed for clearance. To get the brake backing plates off, you need to pull the axle assemblies. Remove the rear axle cover, pinion bolt and axle C-clips; then pull the axles carefully from the housing.
After you have removed the brake backing plates and axles, also unbolt the quad shocks and lower control arms. Your axle housing should look like this now.
The new panhard bar lower control arm mounting brackets use the original control arm holes as index points. Drill out the original hole to 1/2 inch using a stepped drill bit or other sharp high-speed drill bit.
The new lower control arm brackets may require some coaxing. A rubber mallet and--in a few instances--some minor grinding were needed to install these new brackets. Carlos had his work cut out for him, but to his credit, the brackets never became airborne across the shop. Work carefully and you will succeed. Use the included Allen head bolts to mount the brackets.
The panhard bar mounting bracket bolts to one existing quad shock hole, and aligns with the body hole many people use to run nitrous lines. The rest of the holes must be drilled.
The leg of the panhard bracket goes to the tire well. Now is a good time to clean out the trunk.
Using a small drill to make a pilot hole, Carlos drills out the upper and lower holes from the bracket through to the axle housing. Keep working these holes with increasingly larger drill bits until you have reached the 1/2-inch size required by the instructions.
The upper holes are for two stabilizing bolts that are inserted from the inside of the axle housing bracket. Do not forget the washers when installing the nylon lock nuts.
Once the stabilizing bolts are secured, the long Allen head bolt can be removed from the middle hole and relocated to the lower hole, securing the lower control arm. On some control arms, such as our stock rubber bushed lower arms, you need to "kiss" the inside of the bushing with the drill bit to drill away crimp marks that prevent the 1/2-inch bolt from sliding through easily.
There is a specially made washer that must be seated within the rear subframe to secure the panhard bracket. Carlos decides to use the edge of a grinding wheel to make this slot in the access hole at the right side of the hatch/trunk, instead of cutting the area open with tin snips as the instructions suggest.
With the tire and jack out of the way, the six mounting holes are drilled in the tire well for the leg of the panhard bracket. Use the large fender washers included to add support to the area.
Drill the two holes in the rear floor area to secure the panhard bracket above the quad shocks.
The new Koni shocks are adjusted off the car and then installed with their new hardware. Later they can be adjusted by simply unbolting the ends from the axle housing and turning them as the instructions show for the dampening desired.
To finish the rear suspension, the aluminum panhard bar is installed between the axle housing and the frame bracket. Adjust the panhard bar via the included instructions. Reinstall the springs, brakes, axles, and add fresh gear lube to finish the back of the car.
After the rear suspension is completed, Carlos moves to the front of our Modern Mach to swap out springs and struts, and to add the urethane bushings. With a floor jack or jack stand supporting the lower control arm, unbolt the strut from the spindle and camber plates and remove the strut.
With the strut out of the way, the coil spring can be carefully removed. We strongly suggest renting a coil spring compressor for your safety, even though most experienced installers such as Carlos do not.
The new Kenny Brown springs are installed in place of the OE springs. Due to their lower height, they go in much more easily. This kit does not come with new rear springs because lowering springs generally are not needed. Remember, when you installed the lower control arm in the new lower hole, you were effectively lowering the pickup point of the arm an inch.
Install the new Koni front struts with the Kenny Brown urethane bushings. The Koni front struts are easier to adjust with a simple twist of a knob, just like the SVO Mustang.
The Kenny Brown strut brace is installed next. The KB strut brace will clear most intake manifolds, including GT-40, Cobra, Edelbrock and others, as well as most aftermarket blowers. Line up the brace to clear all harnesses and other items, then mark and drill the mounting holes.
The fasteners at the cowl require a little finger work as you snake them through the cowl and into the brace. Use large washers for support or, better yet, cut a piece of steel as a backer plate and drill matching mounting holes in it
The lower crossmember brace simply bolts in place. First, remove the two inner subframe mounting bolts and position the brace. Install the new longer crossmember bolts loosely to hold the brace.
Use the remaining two bolts to mount the short legs of the brace to the matching holes in the crossmember. Tighten all four bolts, and you are done.
Lastly, Carlos undertakes the installation of the jacking rails. The rails are first C-clamped to the pinch weld. The pinch weld and the jacking rails are marked for stripping for proper weld adhesion. All interfering items, such as fuel lines, must be relocated, so check everything while the rails are C-clamped in place.
Kevin uses a wire wheel to clean away dirt and paint from the pinch weld, while Carlos cleans the jacking rails with the sander.
The jacking rails are C-clamped in place again for final welding. Kevin uses the Miller MIG to secure the rails with high-strength stitches every few inches.
All the seams between the welds are sealed by silicone sealer to prevent any water intrusion.
After the sealer has dried, Kevin masks off the pinch welds and blacks them out with low-gloss paint to inhibit rust.
With the new suspension installed and our Modern Mach fresh from the alignment shop, we registered a drop of one inch in the front and in the rear.

Most Mustang enthusiasts build up and enhance vehicle performance in stages as their budget and time allow. Unfortunately, these owners do not always take the next stage in performance from the same book as the previous stage. Too often they install the wrong parts, resulting in slower speeds, worse handling and wasted money.

Many companies have adopted the "package" concept. Some of them, such as Edelbrock, do a great job of including everything you need--from intake manifolds to cylinder heads to the exhaust for a 5.0. As well as these package systems work, however, to achieve the next level of performance, you invariably have to yank just about all the package and start over with a bigger intake, more aggressive camshaft, ported heads with larger valves, etc.

Instead of the package concept for suspension, Kenny Brown's line of Advanced Geometry Suspension (AGS) systems provide a way to do your suspension right.

You can start off with the AGS 1 system and have a budget suspension as a baseline. When you get another bonus check, you can step up to the AGS 2 system, then AGS 3 and so on, never having to remove an already installed AGS part. This makes a suspension system purchase an easy decision because you know you will never regret the money spent. So, follow along as we install a Kenny Brown AGS 3 system on our project Modern Mach.

The AGS 3 system includes Kenny Brown's Double-Cross subframe connectors, urethane bushing package, Koni struts and shocks, strut tower brace, lower crossmember brace, front lower springs, and a panhard bar kit with aluminum panhard bar. The Kenny Brown Jacking Rails, shown in the foreground, are not part of the AGS 3 system, but we decided to add these to the Modern Mach for its safety.