Spark plugs

Spark plugs and gaps:
 
B18A: Bosch W175T35, gap 0.7 mm, 0.65 for 1967 model
B18B: Bosch W200T35, gap 0.65 mm
B20A: Bosch W200T35, gap 0.7 - 0.8 mm
B20B: Bosch W200T35, W225T35 if driven hard, gap 0.7 - 0.8 mm
B20E: Bosch W240T35, gap 0.7 - 0.8 mm
B20F: Bosch W225T35, gap 0.7 - 0.8 mm
B30A: Bosch W200T35, gap 0.7 - 0.8 mm
B30E: Bosch W225T35, gap 0.7 - 0.8 mm
B30F: Bosch W225T35, gap 0.7 - 0.8 mm

These are old Bosch designations, no longer in use. Some replacement designations are:
W175T35: Bosch W5BC
W200T35: Bosch W6BC
W225T35: Bosch W7BC, NGK BP6HS
W240T35: Bosch W8BC

B20 firing order: 1 3 4 2
B20 firing order: 1 5 3 6 2 4