Here is a great calculator. Just plug your numbers in and compare the results.

http://gs.tolan-hoechst.com/tirecalc.htm

You can literally simulate the change in tire envelope in 3 dimensions, not visually, but in numbers anyway.

Most of the 15x7 Jeep wheels I measured last weekend had about 5.375 backspacing and about 1.375 positive offset. Using 4.75 as a reference, it looks like there is a conflict brewing.

Pearl, have you considered 205/60s on a 15x6 inch wheel? That is what put on my sedan last week. My 66 is lowered a bit over 1" and with the Ranger wheels I used, the tire sidewall profile is near optimum and the handling is outstanding. I drove it about 200 miles Saturday to wring it out, everything from crawling along goat trails (really) to freeway speeds up to 90mph.

Steering effort is nearly unchanged from the 165s plus the over all error in the speedo is just -1%.. RPMs at 75mph with the 60s is 2930 vs 2875 with the 165s. With a wagon, RPMs at 75mph with the 60s is 4574 vs 4656.

Here is what it looks like before it was lowered. I'll post some newer pix later today.

Mike