Bolt pattern on a modern Charger is 5x115 and will not work. 5x4.5" works out to be 5x114.3, and yes, that's a big enough difference for it not to be a good idea.
As for the rest, it would really help to know what car you have and what you're trying to do with it. Assuming you're talking about a '67-76 A body you can fit an 18x9 up front with ~6.4" of backspace and go as wide as 275/35/18 with the stock suspension. But if you're talking about a Dart, the widest you can really go in the back with the stock suspension is a 255, so that's the limiting factor.
So, what car do you have and what are your plans for it?
