Will these fit a contour without any rubbing?

http://cgi.ebay.com/ebaymotors/RIMS-17-CONTOUR-FOCUS-MYSTIQUE-OTHER-WHEELS-NEW_W0QQitemZ8016551876QQcategoryZ43957QQrdZ1QQcmdZViewItem

from what the pics say the offset is 49.5 offset but i heard that i wanna stay between 38-43 offset. What will the 49.5 do? Make it stick out?