I don't know which A Racer you have, but the newer ECU that's tiny (like half the size of the stock ECU) is having problems. Rumor has it that is why Hayden's bike shut off at Road Atlanta, and at least one other racer I know had electrical problems all weekend with the new A Racer ECU and DNF. The A Racer guy is at the track every weekend, FWIW. My tuner, Larry Zullo at MotoCorse performance can tune the A-racer. Cooper McDonald had good luck with his, and we had it on Kaleb's bike which is still running strong. But those were the previous version.... If you have a stock airbox, you can take the runners out of that and cut to length and use them on the HordPower- I THINK- the left and right air runners are slightly different, he may use two lefts or two rights or something, I can't remember.
Kae at aRacer has always been easy to get ahold of and get assistance throughout the past few seasons. Fortunately he has been able to make the first couple MA rounds and provide support at the track too. With the aRacer software you can use teamviewer which allows Kae to connect to your program and make changes from his home in CA
Hayden, I'm aware Kae has provided support at MA events, which is good for MA folks but he is not similarly available to those of us who race in lesser series. He doesn't give his cell phone number to everyone. Also, for what it is worth, there are multiple aspects of the SpeedTuning software which Kae does not use or understand, and he hasn't offered to get even basic info about them. He seems to be the sole source of english-language support world-wide from aRacer, so I understand he is very busy. I've gotten a decent tune with my RC Super 2 but it is not as good as it could be and I've had to figure out a lot on my own.
EDR has a head stud kit. I believe it's an ARP kit. Get it, and never worry about the single use cylinder head bolts again.