1971 - factory installed - 383 4bbl automatic
it's pretty straight forward C body OR B&E bodies
if B&E body it's "fresh air" OR "non-fresh air"

383 automatic - C-body blue engine ---------- Carter 6125S ---------- part number 3512 844 on b'cast 44

383 automatic - E & B-body orange HP engine ---------- Holley R4668A ---------- part number 3512 830 on b'cast 30

383 automatic - E & B-body - with "fresh air" (N94/N96) orange HP engine ---------- Holley R4735A ---------- part number 3512 842 on b'cast 42