The firing order for a 1970 Chevy pickup depends heavily on the engine it has. Chevy trucks in 1970 used several different engines. To give you the correct spark plug wire order, I
need to know the engine size and type. (e.g., 350 small-block V8, 396 big-block V8, 250 inline-6, etc.)
Once you provide that information, I can look up the correct firing order for your specific engine.