j35tb and tune?

I've had this j35 tb sitting around for a while now and just been lagging on installing this. Right now my car has an RBC mani with a 3.5" SRI paired with a weapon are header. I'm already tuned to what I have on the car now. I was just curious to know if my car will be running too lean with this TB without a tune? I will also be installing my 3" header back exhaust shortly as well. Any input would be great.

Thanks,
Stefan