The only "thing" with current carbs, if at all is an issue, is that the original FORD Holleys had a throttle that was made to use the production 427 2x4 linkages.
You can use the current throttle arms but they are not going to be "bolt on" and are going to need some "modification" to use.
It can be done. I applied a pair of "converted" (fuel bowls) of '85 Mustang GT carbs to a 2x4 intake. They have annular venturi and factory set to idle at 14.6:1. They actually worked quite well since they are "calibrated" to turn the mains on faster then the old 1850's and thus run just like they do on the mains.
I ran original Holley Custom Shop restored BC-BD's (before Drew was around offering services) and they work quite well on my SMALL block 347 with the C60A T/A intake. So I would say in my particular application, the engine is not over carb'd at all. In fact I would speculate that it is capable of running two double pumpers, providing modification of the fuel bowls is taken into consideration but that is untried.
Drew just had a pair of the original T/A mechanical carbs he restored for Cushman's T/A setup. You can see the physical differences between the "1850's" and the current double pumpers. I believe those are center squirters so not much of a recommended street application unless you were going "pro-street".
Drew may not be the absolute expert on all Holleys but he is highly knowledgable on the carbs that he has done, how they work and why, and how to apply them. I'd go with his recommendations otherwise you become somewhat of an alchamest like me being a rebel within the group of rebels.
That's ok if you are willing to deal with your own self created set backs and careful not to shoot yourself in the foot when you need to finish your "vision" on some sort of a schedule. What happens there is that you discover or maybe more correctly "realize" other possibilities that take you off of the yellow brick road to the Emerald City?
Lots of side streets to investigate.
Then you become like me with the same hair that the "Professor" has in "Back to the Future". Still can't figure out how to make these engines run on recycled garbage though?
