I shipped my stock engine out to Atomic, mine is quiet, its down to personal choice really, I know Atomics products are second to none and specialize in just these engines, and you know everything that's going into the motor. Would you take your engine to someone that knows absolute nothing about the I6 Turbo??? Nizpro & Dynamite, are the only ones I know off the top of my head in Melbourne that have done a few in Melbourne.