crazy talk - 320 into a 360 application?

I'm in a position where I can't afford another (2) 360's
for my twin - someone suggested putting 320's in to "apache-ize" it
until I have more scratch...is this just crazy talk?

People Up to 360's from 320 all the time, but I never heard of
going down to them before - is it: legal, moral, ethical?

Could I just fly for fun for 2 years on these poopers till I have
the big bucks for 360's?? annnd, how many parts are really
interchangable?

Yes this is a wacky one, I expect derision. Just need something to
tell this canard-headed homebuilder know-it-all.

thanks all!
Em