just wondering if anybody knows how well they fit. I think i remember seeing that the 15x4 with 1.75" backspace fit without a spacer and required no grinding . Anybody have any pictures if you have them?

 

The Summit "Star" wheels appear to be the old Weld "XP" series wheels. I thought the XP's would fit better than the real Pro-Stars, because they are one piece, and don't have the big "knuckle" in the back where the 2-piece Pro-Star forging rolls over to transition from the center disc to the rim. Its the thick center disc on the Pro-Stars that catches on the brake pad retainer spring, and the knuckle that gets gouged by the big horizontal bar on the steering knuckle that supports the caliper.

In any case, a 15x4" wheel with a 1.75" backspace is already going to stick out a bit compared to a 15x3.5" wheel with a 1.75" backspace, so adding a spacer might not look too good.

All this is conjecture.... hopefully someone will have bought the Summit wheels and can tell you what they had to do to make them fit.