Talk:Aircraft Conversion/@comment-26662749-20160713143659/@comment-66.171.165.154-20160714220020

It's confirmed by the game's official twitter account.

https://twitter.com/KanColle_STAFF/status/749764315343777792

Translation: The Zeros and the 601 Air Group carrier-based fighters are able inherit their improvement level upon conversion. Converted elite carrier-based fighters will continue to keep their improvement levels. To those who already converted, please do not worry.