Will I benefit from adding more of my Main Vent?

nier01

My main vent is 2 x Gorton #2. The main pipe is about 25 feet. Boiler is over sized and the radiator vents are noisy.
Will I benefit from adding more of my Main Vent?

Jamie Hall

Can you post a picture or two?

KC_Jones

Pictures would help a lot.

EBEBRATT-Ed

Pitch on the header may look weird and I hate weird angles and crooked stuff.

But that being said the equalizer end of the header must be the low end

pictures will help