Carter discontinued the 9410 (which superceded the 9400) in the late 1970's due to lack of interest (many wanted to put two 750's on a 283 - bigger is better). Finding a new carb might be difficult. I simply suggested that this carb would be the easiest to tune, as it was calibrated from the factory for the 283. Used/rebuilt carbs are available, but you have to look.
Also, I would certainly agree with Hotrod Lincoln on the 2 barrel (although I would personally pick a Rochester instead of the Holley). We have had a number of customers get 6800 on a 383 Chevy on 3/8 mile dirt track with a rejetted 400 Chevrolet 2-barrel.
Jon.
