The 18” stock wheels will clear the 6 piston GM Brembos. I don’t know about the designed GTO kit by Brembo or Baer or Wilwood. Pretty sure @evsnova74 is running 6 pots on his 18” wheels…
I am running the 4 pistons because I felt the 6 pistons were overkill for my usage and it adds more money to the project. You’ll still come in cheaper than the BBK offerings however. Anyone upgrading an 04 GTO from stock brakes will instantly notice the difference in braking. It is still by far one of my favorite modifications for looks and function. There is no lack of confidence braking from triple digit speeds.
I am running the 4 pistons because I felt the 6 pistons were overkill for my usage and it adds more money to the project. You’ll still come in cheaper than the BBK offerings however. Anyone upgrading an 04 GTO from stock brakes will instantly notice the difference in braking. It is still by far one of my favorite modifications for looks and function. There is no lack of confidence braking from triple digit speeds.