I think you should do 2 tests...
<insert picture of that nutty professor from "Back to the Future" here>
1) Set up both mics, 1 with each windscreen, as close as possible AB right in front of a speaker and record it. Then listen and see if you can tell a difference.
To be fair, you should swap the screens half way through... there is a distinct possibility your 460's are perfectly matched any more and you don't want that to throw off the test.
2) Again with one of each windscreen, Drive down the road in a car with the mics out the window of the car... speedup very slowly, and yell out the speed of the car as you go "10", "20", etc. See which mic goes nuts in the wind first.
<be sure to yell "Great Scott!" when look at the results>