Your 1976 17056540 Buick 455 California carb should have #75 jets, 49K pri. rods and DB sec. rods.
Your 1979 17059222 Chevy 305 carb should have #71 jets, 40K pri. rods and CH sec. rods.
Since your Chevy carb has the large .120" main air bleeds you can go with the jetting from the Buick carb for your 454. You may find you´ll need larger jets, like #78-#79 after test drive.
Use the CH rods for starters. Later on look for DA, CE or AX sec. rods.
Cut the stop for airvalves to have full flow, aim for 1.37" measured from open valves to back of chokeblade housing.
Transfer choke blade and shaft from the Buick carb for a functional choke on your Chevy carb.
HTH