とばかり（に）・んばかりに: the difference
とばかり（に）N1
Meaning
As if
Past papers
Example
ランナーが通り、ここぞとばかりに声援を送りました。
As the runners passed, the crowd seized the moment and cheered them on.
んばかりにN1
Meaning
As if, As if it were about to, About to
Past papers
Example
小説：「割れんばかりの拍手に部屋は満たされた。」
Novel: 'The room filled with deafening applause, as if it would bring the house down.'
How to tell them apart
「とばかりに」: preceded by what someone seems to be saying; the subject is a person who 'speaks' through actions.
「んばかりに」: the ない form without 「ない」 plus 「ん」; it says something is at its limit and about to happen, as in 「割れんばかり」 (about to break) or 「泣かんばかり」 (about to cry). There are no quoted words.