I don't have an exact answer to your question, but I've been in the tire industry for many years in my past life and you should try and keep the circumference the same front and rear or you will experience a funky feeling rolling down the road
ooops........do a search for dodgestang...he's on several forums and is the author....tracker.....he's gathered info for about 10+ years.....So, Beech, since it's a 404 link, does that mean we don't need to know anything about tires and wheels? *grin*