Bigger wheels for 60 Valiant

Hi everyone.

Yet another wheel/tire question. I searched the forum but didn't really find what I was looking for. This is for my 60 Valiant V200.

What width are the 14" wheels that came on the 68 Valiant? And what is the widest tire I can safely run? And would it make a whole hell of a lot of difference than the 185-80-13's that I have on there now? I have a set of 14" wheels on a parts car I could clean up.

What size 15" tire could I use and still be close to the stock height of the 13" tires? I don't want the car to have that too tall look, I want it to look stock. I'm going to be driving on the expressway a lot and while it doesn't do too badly now, I want to give it every chance to ride and perform as best it can. Also, if I got 15s they'd probably be 6in rims, would that be too wide to use without any bodywork?

Thanks everyone.