So I'm looking to get a bigger stance on my rear wheels for my GTA. I know a lot of people use 4 front wheels with 255/50-16 to achieve this look but I'm wondering if I can use 255/50-16 size tires on my rear wheel and 245/50-16 on my fronts. Does anyone know if that would look good/work?

 

What your asking about is called a staggered look and has been used on muscle cars for as long as they have been around. Yes those sizes will work together but you have to find tires in that 16in. size . There are more tires offered for a 15in. wheel specifically for the old school look. Any way heres what Tire Rack has in that 255/50r16 tire. = http://www.tirerack.com/tires/TireSe...50&diameter=16
Not really any I would use for a all around street tire.
To truly get that look you would have to go to a 15in wheel.

What I prefer is the 235/60r15s in the front and 255/60r15s in the rear preferably with a 7in wide wheel front and a 8in wide wheel rear.
That gives you a difference that can be seen in size without going into a front tire that is to thin/handling/cornering suffering.
This is what that looks like.I built my car around that "Old School" look.=

 

Ron's car is pretty much the poster "old school" thirdgen look, in my opinion. What he has is I think what the OP is asking, so go with what he says.