Eric Vaughn, of Monrovia, California, took my factory late model alloys (6x15) and narrowed them to 4.5 for the front...Heck, you can't buy factory wheels and tires today that balance out that close.
Eric's a bitchin' guy. We have a car with a pair of wheels he made--16" early Ford centers turned down to fit in 4" rims from Volkswagen smoothies. They're arrow-straight, too. Next time you see him ask him if he'll work on some magnesium wheels or powder coat something for you.