LS6 Carb and manifolds

[Richls5]

I recently bought a Ls6 m22 car it doesn't have the correct holley carb or exahaust manifolds. ive found a few carbs and before I drop more than I think its worth really on a used in need of rebuild carb I want to make sure I get the right one. the engine is dated march 23 1970. my understanding is 4557 GG carb is what I need I've found several. The closest to march I've found is a 012 dated which would be January second week of in 70 right? I found one from 427king dated 9A3 would that be third week November 69? thanks for any and all help i'm very green to this stuff. 427king also has a set of manifolds dated second week of febuary 1970 I just would like to make sure before I pay a lot of money for any of this stuff i'm putting the correct dates on the car thank you