ORIGINAL: Tall Paul
---- There's no real quantitative way to check the effect on a model, it will be up to you to decide what you like.
There won't be any serious bad effects in any event.
Actually, there can be very serious effects if you don't get them "square" to the slip stream, or slightly "toed-in". If you somehow have one (or both) of the tip-plates slightly toed out you will have a violent roll response.