The proper tire size for a 1998 Pontiac Transport is P205/70R15. This info is on a sticker placed on the driver's door jam.
i believe stock size is 205 75 15
34mm
6.70x15
215/70-15
1949 Pontiac Chieftain Eight Series 27 tire size is 7.1 x 15".
22 and 17
Listed in your owner's manual and on the driver's door post.
225 / 50r 16
P215/60R16
3x3's
One that fits.......
P225/60R16 is the proper factory tire size.