I know someone who put 2 Ede 650 AVS’s on a 471 Hemi with ported heads and a roller cam.
They had to jet way way down.
With the ootb jetting, the A/F ratio was in the 10’s.
On the other hand, I had a 557 with 2 Carter 750’s on the dyno once....... couldn’t get it rich enough.
I ended up with .119 jets in all 8 holes.