I've been having a highway speed vibration issue with the OEM wheels and stock size (255/50ZR17 Riken Raptor ZR A/S) tires on my 1995 Impala SS that I haven't been able to eliminate with an alignment and balancing. The technician who last balanced the wheels and tires noted that all 4 had lateral run-out that exceeded GM specs, so maybe that was part of the problem. These wheels were purchased direct from GM 20 years or so ago, have roughly 30K miles on them, and have never been hit, so I have no idea why they're not true, but anyway...
It's been getting harder and harder to find tires in the OEM size, so I decided to try a different size with the same diameter to keep the speedometer accurate. I decided to go with 255/45ZR18s at all four corners. I selected a set of 4 Continental ExtremeContact DWS06 tires.
That meant looking for 18" wheels. I wanted hub-centric wheels if possible, so after a lot of looking I decided to use US Mags Standard U104 wheels (18x9, offset -12, backspace 4.53, hub size 78.10, part number U10418907352). The combination of offset and backspace means the tires sit about 0.5" further out of the wheel well, but it all fits just fine.
I bought the whole kit as a package from Extreme Customs
for $1,585.26, with center caps, lug nuts, shipping, and high speed road force balancing included. I just finished a road test after installing them, and the vibration issue is gone. I also have a much larger selection of replacement tires in the future, and my speedometer is still spot on. Overall, I'm happy with the swap. One of these days I'll see about getting the OEM wheels repaired, but with the limited selection of tires I don't know if I'll ever go back to using them.