Hello gents, new to the forum, but not new to cars.

Anyway, Ive come across a decent 911 Turbo Carrera and after looking online, Ive noticed different ratings and specs. Some say 285hp, some say 320hp. So, I was wondering what the true specs are and if there is anything to look for in the car.

Im quite familiar with the turbo world, so what size turbo is on these, and I assume there are turbo upgrades? If so, which turbo works well (KKK) ? Are these blocks strong, as in I can turn the boost up to what psi?

Basically Im looking for the "detailed" details on performance.

Thanks