Well i came across some old mustang wheels, which i have had redrilled to the proper lug arrangment. 2 of the tires were in very good condition, and 2 werent. So i mounted 225 60 R16s and put them on back. From my memory those are the same diamter as stock 15's and 16's for a bird. Now the front wheels have 225 50 R 16s. Noticbly smaller in diameter. Now i put the smaller wheels on the front because i didn't want to have to screw with the speedo and all that, and it would just look wierd if i had them on back. But is there any problems with having a smaller diamter tire than stock on the front? I can't think of anything more than more wear at higher speeds?