That can be flipped. Because it has a lot of angle, the difference will be pretty substantial. Before getting into that, do ensure that you understand how threadless headsets (fork bearings) work, because once the stem is removed from the fork, your fork bearing may go out of adjustment. If in doubt, ask the bike shop to kindly flip the stem for you.

Here's Park Tools' info on headset removal, installation and adjustment. http://www.parktool.com/repair/readhowto.asp?id=65 For your purposes, look at the adjustment stuff.