per my interpretation of the Parts Catalog ... there are five 4bbl carbs for ECS (N95) 383s. HP & non-HP. A/C doesn't affect the carb choice.
383 manual - E & B-body - with ECS (N95).......... orange HP engine 335hp ---------- Holley R4217-A ----------part number 3418 537 on b'cast 37 383 Manual - E & B-body - with ECS (N95) & with "fresh air" (N96). orange HP engine 335hp ---------- Holley R4738-1A ----------part number 3512 974 on b'cast 74
383 automatic - E, C & B-body - with ECS (N95)................... blue engine 330hp ---------- Carter 4734S ----------part number 3418 541 on b'cast 41
383 automatic - E & B-body - with ECS (N95)..................... orange HP engine 335hp ---------- Holley R4218-A ----------part number 3418 543 on b'cast 43 383 Automatic - E & B-body - with ECS (N95) & with "fresh air" (N96). orange HP engine 335hp ---------- Holley R4739-1A ----------part number 3512 975 on b'cast 75
