throttle bodies
 

im about to buy a new throttle bodie its a twin-bore 52mm for my 2007 mustand gt roush, would i have to put a new tune on it or is it a plug and play.allso i cant find the specs on whats on it now, its all stock 4.6, 3 valve.and would it incress the hp,,,370.00 dollors worth.(is it worth it) any imput thanks

Unless your motor is super/turbocharged your wasting your money. The stock throttle body is plenty big on a NA motor.