you know what you need rhart... SRT8 brakes!

SRT8 brembo brakes + 370Z rotors = pavement tearing stopping power

link to someone who has done it - 300zxClub.com (Nissan 300ZX Forums)

Definitely on my to do list for both my 300zx project and future 240 project.

and some info on doing a brembo rear from an STI - http://zilvia.net/f/tech-talk/93748-...se-do-yet.html

It is for a 300zx, but given how relatively simple it is to swap the 300zx stuff to a 240, it wouldn't take much to put these brakes on a 240.
Crazy stopping power right there.