Your NOS #340734 is a service replacement part! It replaces a lot of earlier parts in the system with a one size works for most approach. Like I've tried to tell people so often a dealer or claimed NOS part rarely is a direct duplicate of a period production part.
Run the P/N through
http://gmpartswiki.com using the "search" function and "all". Then you can see applications and supercessions with that number.