Manual Brake Conversion Kit1979-93 Ford Mustang Note: Does Not Include a Provision for a Brake Light Switch. Aerospace Components AC-MBC7993 Manual Brake Conversion Kit. 1979-93 Ford Mustang Note: Does Not Include a Provision for a Brake Light Switch. Around here, we don't just sell parts - we rely on them when driving our own cars around racetracks, dirt trails, and interstates across the country. Parts may be our business - but grease, fuel, exhaust, power, and speed are what we live for. Today, more than 350 people are employed by JEGS and the business draws in hundreds of thousands of customers each year. Yet, we maintain the culture stared by Jeg Coughlin from the very beginning: a family-run performance shop that preserves a trusted relationship with each and every customer.