What is the push-rod order for a 31L engine in 1996 Chevy Lumina?
The 1996 Chevy Lumina did *not* use a 31L engine. The 3.1L (3099 cc) engine in that era was a V6, and V6 engines don't use pushrods in the same way a V8 does. They use a different valvetrain arrangement, usually overhead camshafts (OHC). Therefore, there's no pushrod order to define.