Wheel report --
I just last week took delivery from fleabay a pair of 16x6 - 0 offset aluminum wheels listed as trailer wheels. They have 10 cooling holes. I believe you can also get steel wheels of the same description but probably not with hubcap clips. I had been using 16x7 aluminum wheels with a 0 offset and no holes. The 6 inch wheels effectively move the center-line of the tire 1/2 inch closer to the kingpin. It drives so much better I can't believe I put up with it the old way as long as I did. I had the same tires mounted on 8 inch rims and it was almost un-drivable at highway speeds. I only made one 200 mile trip with it like that before putting the 7 inch wheels and tires back on but the 6 inch wheels are the ticket. The original 5 in. wheels have a 7/16 offset as compared with the new wheels 0 in. offset. That apparently gave center point steering. Zero offset is just fine. Negative 1/2 inch is somewhat tolerable and negative 1 in. is probably dangerous once you get tired or get surprised by ruts in the road.