A tune, exhaust, and cai will pretty easily put down 416 to the wheels.
1/4 time will be completely based on your driving abilities. I put down 500 to the wheels and run 12.6....with your mods, a 12.3-12.4 should be had with a decent driver. A good driver might be able to get closer to a 12.0.
However, if you had a picture of your engine bay, we could pretty easily tell you what mods you might have under there....
I am going to assume at least a K&N air filter, x pipe as you said, and possibly a cat back. WE would need to see your exhaust tips to know that.