Standard Ignition Distributor Cap P/N:GB-421
Help keep high-voltage spark flowing to every cylinder with the Standard Ignition Distributor Cap GB-444. It is a direct-fit replacement for the listed applications, including the 1973-1980 Mercedes-Benz 450SL, 1981-1985 Mercedes-Benz 380SL, 1984-1985 Mercedes-Benz 500SEL and 1978-1984 Porsche 928. See the Buyer's Guide tab for the full list and engine details.
The distributor cap works with the rotor to carry high-voltage current from the ignition coil to each spark plug wire terminal in firing order. A cracked cap, carbon tracks inside it, or corroded terminals can disrupt that path.
Signs this part may need replacing: misfires, rough running, hard starting, visible cracks, carbon tracking inside the cap, or corroded terminals. If a worn cap is the cause, this part replaces it. Inspect the rotor and plug wires at the same time.
Fitment:
Interchange: C639 · 0290004500 · 0290004502 · 0290004505 · 1235522293 · 290004500 · 290004505 · RB942 · EP739 · 12302976 · 0001583402 · 0001584202 · 1583402 · 92860290200
This part cross-references / interchanges with the following part numbers:
What does a distributor cap do?
It works with the distributor rotor to carry high-voltage current from the ignition coil to each spark plug wire terminal. This delivers spark to the cylinders in the correct firing order.
Which vehicles does the GB-444 fit?
It fits listed Mercedes-Benz models, including the 1973-1980 450SL, 1974-1980 450SEL and 1981-1985 380SL, plus the 1978-1984 Porsche 928. See the Buyer's Guide tab for the full list.
What is the cap made of?
Standard Ignition builds its distributor caps from high dielectric strength, glass/mineral reinforced polyester resin. The material is designed for less carbon tracking and greater resistance to electrical breakdown.
What are signs a distributor cap may need replacing?
Misfires, rough running, hard starting, cracks, carbon tracks inside the cap, or corroded terminals. Diagnose the cause first, because plug wires, the rotor or the coil can produce similar symptoms.
What part numbers does it replace?
It cross-references numbers including C639, RB942, EP739, 0290004500 and 0001583402. The full list is on the Interchange line in the description.
WARNING: These products can expose you to chemicals including lead and phthalates, which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.