Cylinder Head BoltsDetroit Diesel 60 Series 11.1/12.7/14.0L38/Pkg. Clevite MAHLE GS33539 Cylinder Head Bolts Detroit Diesel 60 Series 11.1/12.7/14. Detroit Diesel 60 Series 11.1/12.7/14.0L. 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.