It has been at least 30 years, but I will never forget my old Wimbledon White '68 Mustang fastback, a Detroit car with significant amounts of floorpan and torque box rust-and this was in 1977. I had just installed a fresh 289 built by Jan Morris at Precision Engine Machine. Jan fitted my 289 with a new Hays flywheel, clutch, and three-finger pressure plate, a 3,000-pound monster designed for drag racing.
When it was time to take my 289 out for a spin, you can imagine my disappointment when the clutch equalizer bar folded over like a wet piece of pasta. I ordered a new equalizer bar from my Ford dealer and it, too, promptly bent over, rendering the Hays clutch useless and stopping my fastback right in its tracks. I had the car towed up to Belair Phillips 66, where Mike Smigielski welded reinforcement iron to my equalizer bar. I never had a problem with the clutch again, except for extreme left knee joint erosion in traffic.
What I wouldn't have given for Modern Driveline's clutch cable conversion kit in 1977. It would have made light work of that Hays racing clutch for one thing, and Mike wouldn't have had to fire up his welder.
Modern Driveline's cable clutch kit is easy to install because everything you need is included as long as your Mustang is equipped with a late-model 5.0L-style bellhousing designed for clutch cable operation. The kit includes a firewall bracket/plate, a cable with adjustments at both ends, a heat insulator wrap, an adjustable clutch pedal mechanism, a clutch rod opening rubber plug, and all installation hardware.
How involved the installation will be depends upon your Mustang. The Modern Driveline cable clutch kit will not work with some of the larger-diameter power brake boosters. We didn't have a problem with installing it on a car with a Trans Am Racing power brake booster, and we also know it works with some of Stainless Steel Brakes' boosters as well as any stock booster.

Begin with a 1/4-inch hole,...

Begin with a 1/4-inch hole, then, using a Uni-Bit, bore a 9/16-inch hole. This is where the clutch cable penetrates the firewall.

We've already removed the...

We've already removed the master cylinder and old clutch linkage. The firewall bracket is positioned in order to mark the firewall for drilling.

We've positioned the firewall...

We've positioned the firewall bracket and clutch cable to check freedom of cable movement. The cable must not touch the firewall.

This is the way your cable-to-bracket...

This is the way your cable-to-bracket installation should look. Modern Driveline provides a rubber O-ring to retain the cable. However, in some environments, such as Los Angeles with high ozone levels, we suggest the use of a C-clip.

Our Trans Am Racing power...

Our Trans Am Racing power booster is installed next. We like the Trans Am booster for its compact design and easy fit. You can use this booster with your Mustang's manual brake pedal.

Inside, the Trans Am power...

Inside, the Trans Am power booster installation looks like this. Studs penetrate the firewall through existing holes. If your Mustang has manual brakes, you will have to drill out the hole at 6 o'clock.