You need to specify the *engine* in your 1986 Chevy to get the correct spark plug wire firing order. Chevrolets in 1986 came with a wide variety of engines (V6, V8, inline 4, etc.). Each engine has a different firing order.
Please provide the engine displacement (e.g., 2.8L, 3.8L, 5.0L, 5.7L, etc.) or the engine code (often found on a sticker under the hood or in the glove box). Once you give me that information, I can provide the correct firing order.
