I recently purchased an Arrington 426 engine upgrade. Tommy Pike in Greenville, SC installed and setup for me. The only problem I had was to get the engine passing emissions in NC. When I purchased the engine , I was assurred this was not a problem. I received the car back and was told to drive it a few weeks while waiting on the new tune from Arrington. Long story short, I was quiet for 2 months and during August it came to weekly phone calls. I was promised "Will be sometime next week" countless times. But my story has a happy ending "SO FAR", I received the tune at the end of August, car still runs well and it will pass emmisions. So it's good driving a 650+ HP on the street and it be street legal.