It's an NA motor so you're fine. More boost than stock + KR = bad. But you don't have that problem. I wouldn't worry about it unless you're planning on modding or doing something special to it. Even stock 3800SC cars knock. I saw 4-5+* of KR stock. No biggie.
Also if you're worried about it, and you don't already, Put in some 93 instead of 87.