Upgrading wheels on 70 swinger

I'd stick with 17x7's in the front and 17x8's in the back. It just looks better. You don't mention what you're putting in the back or what aspect ratio tire you intend to use.

On my 71 Dart I have 215/45-17 front & 235/45-17 rear. The front have plenty of clearance and the rear has approx. 1/2" sidewall clearance and is tucked up nicely in the wheel well. Overall tire height is 25". The wheels has recently been updated, but still the same size. This should give you a good idea of what it should closely look like.

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