Is it safe to redirect other similar domains I own to a my brand website now ? can it have a positive or negative impact on the ranking. I understand that, Google handles the 301 redirection differently now.
Example, I own the following websites...
Now, I want to retain only one domain which is mybrand-shoes.com and I want to redirect blackshoes.com & premiumblackshoes.com to mybrand-shoes.com.
I currently use and built a brand around the domain name, mybrand-shoes.com. Site 1 and 2 has lots of back links which were built using grayhat technique. If I redirect site 1 and 2, then mybrand-shoes.com might get lots of backlink.
All the above domains are 8 years old. I am sure, someone might have done similar case study here.
Someone please help me.