None, the GTs heads are different, different cams, and MUCH shorter exhaust.
Compare a stock SBC to a SBC with heads and cam and tell me the sound difference.
turbo turbo turbo
True, it all starts at the motor. That GT motor is a lot higher revving to I believe. It’s making another 200HP, so many internals are quite different I’m sure. Ford can’t just be boosting the hell out of it and expect it to live a long life.