What is the firing order Chevy 1990 truck?

The firing order for a 1990 Chevy truck depends entirely on the engine. Chevy trucks in 1990 used several different engines. You'll need to specify the engine's displacement (e.g., 4.3L, 5.0L, 5.7L, 6.2L) or the engine code (found on a sticker under the hood or on the engine itself) to get the correct firing order.