I'm picking up a 78 this weekend, and when the time comes for some new wheels and tires. I want to run at least 17x7 up front ( preferably 17x8 ) and at least 18x9 ( preferably 18x10 ) in the back. Will I have any issues running either of these setups?

 

You should be fine with the right tires. I ran 18''x9'' all around on my 72 for years with 245/40/18 no problem. The 72 have a lower fender cut line than the 78 Monte's. The overall diameter will be 25.7'' with a 18'' on 245/40/18 tire. The OEM diamenter is approx. 25.6'' on a 235/60/15 tire. The two are the same. You just getting more rim than tire going 18''. As you can see your able to go with a taller tire on a 18'' if you choose too and still have plenty of room.

18''x10'' is a custom built 2 piece rim. Most standards will be 18''x9'' The price will be very high for 18''x10''. My 2 piece billets cost me $2200 with tires and they were either 18''x9 or 18''x8.5''. If your interested I will sell them they are in excellent condition.

 

Okay, I just didn't know if they would bump any of the suspension being wider, a buddy of mine just bought some wider rims than stock and he can't run em cuz the tire hits his spring seats when it flexes. I suppose I just need to pay attention to the offset.

And I appreciate the offer, but I already know which rims I'm going to get when the time comes, which won't be for a while anyways, but thanks again! and I love the look of your monte.