I run twin 94s on an 8ba manifold. This is on a 239 59A in my 33 coupe. I have stock jets which are 50s or 51s. I run stock power valves too.
It runs great.
I would suggest you try stock first and then try something else if it doesn't work.
The thing is, 94s will run rich for many reasons. Running rich for any one of these reasons will make you try leaner jets and try and compensate. But that's wrong. You need to find why it is running rich.
Float height. Leaking needle valve. Fuel pressure too high. Punctured float. Ruptured power valve. Wrong power valve seat shape. Wrong power valve gasket. Cracked power valve body. Warped lower and middle body castings.
I have made videos showing machining the castings to ensure a good seal around the power valve vacuum chamber. A leak here will stop the power valve from closing and give an over rich mixture.
When I did my dual conversion I first ran each carb on a single intake and made sure they both ran perfectly. Only then did I try them as a pair.
I hope this advice is some use to you.
There is a link to a 94 teardown and reassembly video here:
https://www.fordbarn.com/forum/showthread.php?t=305182
Click the link in the first post
Mart.