Description

Autolite 847 Copper Resistor Spark Plug – Classic GM Applications

Condition: New Old Stock

Autolite 847 copper-core resistor spark plug for compatible Buick, Oldsmobile, Pontiac, and Cadillac gasoline engines. Features nickel electrodes, a ceramic insulator, and a flat gasket seat. Its resistor construction helps suppress ignition-related electrical interference.

Suitable for maintenance or restoration of classic GM vehicles that specifically call for this plug. Sold individually—one spark plug per purchase. Confirm the engine, ignition system, and required gap before ordering. 

Specifications

Brand: Autolite

Part number: 847

Type: Copper-core resistor spark plug

Center electrode core: Copper

Electrode tips: Nickel

Resistor: Yes, approximately 5,000 ohms

Thread size: M14 × 1.25

Thread reach: Approximately 9.5 mm / 3/8 inch

Hex size: 13/16 inch / approximately 21 mm

Seat: Flat gasket seat; washer included

Heat range: 5

Terminal: Fixed, non-removable nut

Ground electrodes: One

Catalog preset gap: 0.070 inch / approximately 1.78 mm

Quantity: One spark plug. 

Selected fitment

Buick LeSabre 1981–1984: 5.0L gasoline V8

Buick Riviera 1981–1984: 5.0L gasoline V8

Buick Regal 1983: 5.0L gasoline V8

Oldsmobile 98 1981–1984: 5.0L gasoline V8

Oldsmobile Custom Cruiser 1981–1984: 5.0L gasoline V8

Oldsmobile Cutlass Supreme 1982–1984: 5.0L gasoline V8

Oldsmobile Delta 88 1981–1984: 5.0L gasoline V8

Oldsmobile Toronado 1981–1984: 5.0L gasoline V8

Pontiac Firebird 1978–1979: selected 6.6L gasoline V8 applications

Cadillac Eldorado 1979–1980: 5.7L gasoline V8

Cadillac Seville 1978–1980: 5.7L gasoline V8. 

Fitment note: Engine origin, cylinder heads, ignition system, and production date can affect compatibility. Catalog gap requirements vary, including 0.060 and 0.080 inch; use the vehicle’s service specification. Diesel versions are excluded.