1:350 scale aircraft used on a 1:400 scale aircraft carrier will appear 12.5 % too large.
(400-350)/400 =.125
The choice is yours. I try not to mix scales with differences greater than 10%. IMO the appearance is too visually jarring.
Conversely, using 1:400 scale aircraft on a 1:350 scale carrier, they will only appear 7.6% too small
(350-400)/350 = -0.076
Math! Who said there would be math involved im modeling!