Max wheel size/width on 73 Trans Am

[v8 stingray]

Hi Guys,



Apologies 1st - this question has been probably asked a million times already!

I have a '73 TransAm 455 (sadly a 400 lump now) which I'm restoring at the moment and I'm planning on going the pro-touring route.I like the staggered/deep dish look of the TransAm in the picture below and would like to know what are the maximum wheel widths/offsets that I can go with on a stock car to get a similiar look? Ideally, I'd like to go 18" all around.

I'm assuming the mini-tub route allows for even wider wheels at the rear, but does that mean a rear axle change? thanks!