Most 352-4v,390-4v,410 and 428 were equipped with the Autolite 4100 until 67,Ford was looking for better emissions with the 4300.the 4300 wasn't half the carb the 4100 was in terms of performance and reliability.
The 390,410 and 428's suffocated while trying to breath through the 4300's limited bores.
Many of the 4300's were tossed and replaced with a Holley 1850.
Ford improved the 4300 following 67 but it's a tricky carb to tune.
The 4300 was inlarged to 600cfm in 69 which helped a little and continued for the 429/460 until 1975,when it was replaced with the 4350.
Ford engine Parts Interchange.
Keepin it square!
El Guapo out!