You'll be fine. I stayed in Nepal for 9 months while on GC. I did it again (10 months) and that is when I was grilled by border patrol. I had a valid reason, though and they advised me to apply for reentry-permit (that's valid for 2 years) if I had plans of longer stays.

Don't spend more than 6 months at a time if you have plans to apply for citizenship as soon as you're normally eligible as it will reset eligibility.