Maybe.
Your question is hard to answer. You seem to be asking "would 4.3GHz with negative voltage offset be worse or better than 3.8GHz with default voltage?"
Both an increase in voltage AND an increase in frequency have a negative affect on a CPU, however a small overclock with a voltage DECREASE is hard to say.
Regardless, I wouldn't worry too much since statistically you'd likely get well over FIVE YEARS out of it. Your motherboard is likely going to die first.
BTW, a Hackintosh is technically illegal. I hate to be the jerk that points out that we don't discuss illegal activities here.