I'm currently building my first rod, a 1947 plymouth special deluxe coupe and absolutely will have the top chopped 3"-5". I know that the style of top this generation of cars had makes them more difficult to accomplish but hey....these are hot rods we're talking here, it's all about personal tastes and no rules right.
I've seen a couple of 40's mopars with chopped tops and they look awesome but thats just me, I'd think a school bus would look great chopped!!
Any way there's my 2 cents, good luck with your ride either way.