IGNITION
Like all PONTIAC engines since 1955, the firing order sets is: 1-8-4-3-6-5-7-2, all by turning it counterclockwise. Note that the cylinder number 1 is the next driver in front of the engine (the same location on all V-engines) or just the first behind the power steering pump.
Oldsmobile V8 engines (260, 307, 350, 403 and 455ci) is identical to the pontiac: 1-8-4-3-6-5-7-2 counterclockwise.
Buick V8 engines (350ci): 1-8-4-3-6-5-7-2 clockwise.
Chevrolet V8 engines (305 and 350ci): 1-8-4-3-6-5-7-2 clockwise.
For 1975, the type of spark plug changes because of the HEI distributor.
Identification and decoding of spark plug:R 4 5 T S X
1 2 3 4 51 - "R" indicates the type of resistance => internally.
2 - "4" indicates the diameter of the pellet. => here is 14 mm.
3 - "5"=> temperature range: 1 => 9, cold => hot.
4 - "TS" for "TAPERED SEAT" => conical seat.
5 - "X"=> Special electrode spacing, here 0.060" or 1.52 mm
Spark plug type / timing setting YEAR ENGINE Type Electrode spacing timing manual trans timing Auto trans 1970 350 AC R46S 0.035" (0.89mm) 9°@ 800tr/min 9°@ 650tr/min 400 (265hp) 9°@ 800tr/min 9°@ 650tr/min 400 (330hp) AC R45S 9°@ 950tr/min 9°@ 650tr/min 400 (345hp) AC R44S 9°@ 950tr/min 9°@ 950tr/min 400 (370hp) 15°@ 1000tr/min 15°@ 750tr/min 1971 350 AC R46S 0.035" (0.89mm) 12°@ 800tr/min 12°@ 600tr/min 400 (265hp) 8°@ 600tr/min 400 (300hp) 12°@ 1000tr/min 12°@ 700tr/min 455 (280-325-335hp) 12°@ 1000tr/min 12°@ 700tr/min 1972 350 AC R46TS 0.040" (1.01mm) 8°@ 800tr/min 10°@ 625tr/min 400 (175hp) 10°@ 625tr/min 400 (250hp) AC R45TS 8°@ 1000tr/min 10°@ 700tr/min 455 8°@ 1000tr/min 10°@ 700tr/min 1973 350 (150-175hp) AC R46TS 0.040" (1.01mm) 10°@ 900tr/min 12°@ 650tr/min 400 (170-230hp) AC R45TS 10°@ 1000tr/min 12°@ 650tr/min 455 (350hp) 10°@ 1000tr/min 12°@ 650tr/min 455 (310hp) AC R44TS 10°@ 1000tr/min 12°@ 750tr/min 1974 350 AC R46TS 0.040" (1.01mm) 10°@ 900tr/min 12°@ 650tr/min 400 (170-190hp) 10°@ 900tr/min 12°@ 650tr/min 400 (225hp) AC R45TS 10°@ 1000tr/min 12°@ 650tr/min 455 (250hp) AC R46TS 10°@ 1000tr/min 12°@ 650tr/min 455 (290hp) AC R45TS 10°@ 1000tr/min 12°@ 750tr/min 1975 350 AC R46TSX 0.060" (1.52mm) 12°@ 775tr/min 16°@ 600tr/min 400 AC R45TSX 12°@ 775tr/min 16°@ 650tr/min 455 10°@ 675tr/min 16°@ 675tr/min 1976 350 (155hp) AC R46TSX 0.060" (1.52mm) 16°@ 550tr/min 350 (175hp) 16°@ 600tr/min 16°@ 600tr/min 400 (185hp) AC R45TSX 12°@ 775tr/min 16°@ 575tr/min 455 12°@ 775tr/min 16°@ 550tr/min 1977 301 AC R46TSX 0.060" (1.52mm) 16°@ 800tr/min 12°@ 550tr/min 305 (Chevy) AC R45TS 0.045" (1.14mm) 10°@ 1000tr/min 10°@ 1000tr/min 350 AC R45TSX 0.060" (1.52mm) 16°@ 575tr/min 350 (Chevy) AC R45TS 0.045" (1.14mm) 350 (Olds) AC R46SZ 0.060" (1.52mm) 20°@ 575tr/min 400 AC R45TSX 18°@ 775tr/min 16°@ 575tr/min 403 (Olds) AC R46SZ 20°@ 600tr/min 1978 305 (Chevy) AC R45TS 0.045" (1.14mm) 4°@ 500tr/min 350 (Chevy) 6°@ 700tr/min 8°@ 500tr/min 400 (180hp) AC R45TSX 0.060" (1.52mm) 16°@ 650tr/min 400 (220hp) AC R45TSX 18°@ 775tr/min 403 (Olds) AC R46SZ 20°@ 700tr/min 1979 301 (140-150hp) AC R46TSX 0.060" (1.52mm) 14°@ 750tr/min 12°@ 650tr/min 305 (Chevy) AC R45TS 0.045" (1.14mm) 4°@ 500tr/min 350 (Chevy) 8°@ 600tr/min 400 AC R45TSX 0.060" (1.52mm) 18°@ 775tr/min 403 (Olds) AC R46TS 18°@ 550tr/min 1980 265 AC R45TSX 0.060" (1.52mm) 10°@ 700tr/min 301 12°@ 500tr/min 301 Turbo 8°@ 600tr/min 305 (Chevy) AC R45TS 0.045" (1.14mm) 4°@ 550tr/min 1981 265 AC R45TSX 0.060" (1.52mm) 12°@ 600tr/min 301 12°@ 600tr/min 301 Turbo 6°@ 700tr/min 305 (Chevy) AC R45TS 0.045" (1.14mm) 6°@ 800tr/min 15°@ 1100tr/min