Carb conundrum

Captainkirk said
Perceptive you are...

LMAO!

Captainkirk said
What happens if those areas are left uncovered? Does anyone know?

You mean the are under the carb itself?
Nothing.
The effect performance?
Probably a few extra rpm at best, a slightly better balance of the carb since the carb see's the entire engine.

Captainkirk said
Where did you find those numbers published, YR?

A lot depends on the build itself. Considering yours is a very mello build, those numbers are probably pretty accurate.