427's & TKO-600 OD gearing

[GoDadGo]

I'd play with the carburetor & timing a bit more before I started changed parts.

1. Unfortunately not a lot of today's mechanics know how to set up a Holley or any carburetor, but they can be tuned.
2. I honestly suck at it so I installed an Edelbrock AVS, but have had to do some tuning to make that carb run right.
3. Don't throw the baby out with the bath water just yet because I think you can make it run a lot better than you think.
4. My entire set up is way more radical than yours so I really think this issue can greatly improve.

Here is a little video from Jegs that may help:
https://youtu.be/xscWLSpB5Go

Another option would be do what I do when I'm mechanically frustrated and sleep at a Holiday Inn Express.

Good Luck!