Wheel fitment question

[HighlyBlest]

Absolute noob when it comes to offsets and wheel size, any advice would be appreciated.
Would you suggest a 25mm or 35mm offset for 19x8.5 wheels (square set up) for a stock 2012-2014 gt? And also what would you suggest if it had the brembo brakes?

 

[AHaze]

I always reference a stock GT500 for these types of things. They came with 9.5" wide wheels with 45mm offset. An 8.5" wide wheel would need 32 mm offset to have the outside lip sit in approximately the same place so 35mm will tuck about 1/8" more and 25mm will poke about 1/4" further out. Pick whichever you would prefer.
I'll answer your second question with another question: Why saddle a Brembo pack car with a wheel that narrow? They came with 9" wide wheels. I personally think a 9.5" wheel with 275s all around is the bare minimum for this chassis, drag cars excluded of course. If I'm buying new wheels for my car, nothing under 10" wide is even up for consideration.