NIW doesn't rewuired 180 days

http://www.hooyou.com/niw/I-485%20filing%20memo.htm

3. The Portability Rule
For all those aliens who are beneficiaries of employer-sponsored I-140s, namely, EB-1 (b) (Outstanding Researcher or Professor), EB-1(c), EB-2 (except NIW) and all EB-3, current immigration law allows them to change employers 180 days after the date of filing of I-485 adjustment of status. This has been called the portability rule.