Autolite 4300 info

[FirstEliminator]

Hey guys,
    Looking for any tips or methods on rebuilding an Autolite 4300.  I've heard of these carbs being modified to overcome some of the issues to be a good working carb in a mild performance application. A few months ago I picked up a couple 4300's from a guy running a 70 Mustang in the FAST series. He had to run an Autolite carb. He said it was ported and other mods done that he was running in the 11's. I'd like to find further info on identifying and correcting the shortcomings of this carb.

Thanks,
    Mark

[FirstEliminator]

Seems like not too many people fool around with these and the ones that do aren't talking.

[Rory428]

There may well be some people well versed in the Autolite/Motorcraft 4300 carbs, but back in the mid 70s when I had my 70 M code Mustang, I swapped out the 4300 for the factory 600 Holley from my 66 GTA 390 Fairlane. Ran much better, and picked up almost 3 tenths at the dragstrip. In Stock and Super Stock, where the factory style and size carb is required, virtually nobody that I am aware of, runs a Ford with a 4300A carb. All the 351C 4 V engines came with 4300 carbs, but due to a loophole, the 71-72 Mustangs are allowed to use a "superceded" Holley carb, but 70s are not. Lots of 71-72 Mustangs in Stock, but no 70 351C models. Probably the fastest 4300 equipped class car that I am aware of is Scott Pearson from Minnesota, who races a 70 AMX 360, in the mid 10 second range. He, or whoever does his carbs obviously has a handle on them, but the Holley is just a simple cure.