What size tires will fit on stock dart 15" wheels?

I am having a lot of trouble finding out what tires will fit on my dart... I am going to order 15x8 rallyes for the back with 4.625 backspacing n +3mm offset, n 15x7's for front with 4.25 backspacing n +6mm offset...

I think these wheels will fit, as the rear end mounts/springs have been moved in a bit making a little more room for the rear wheels, but I am not sure exactly how much width was gained, as the previous owner was the one who did the alteration...

Can anyone tell me what will fit with these wheel sizes as far as tires go?
And am I off base with these wheel dimensions?:rolleyes: