Website Migration SEO Concerns

I have been doing SEO for a while, but there are always questions that come up and I was hoping someone could give some advice on the current project I'm working on.
I have a client that would like to migrate his site to a new domain. His current domain appears #4 for the most popular keyword phrase, which is also his domain name.
So, for hypothetical example, his site is widgetsdetroit.com where he appears in the fourth slot for users searching "widgets detroit" on Google. He'd like to migrate his site to detroitwidgets.com.
How will this affect the Google search ranking? It will be a carbon copy of the site, but I realize he will probably get knocked back for basically resetting the clock for the site.
How important is word order for domain name keyword optimization? Also, since there will likely be a delay in the transistion, it's possible he will have both sites up at the same time for a little while. Does Google frown upon this in any way?
Thanks in advance!

 

Hi,

1. A 301 redirection from the old domain to the new domain would be necessary for keeping your current SEO efforts.
2. The sequence of keywords in domain name would have direct impact on the ranking for your targeted ones.
3. Having both sites online at the same time would not hurt your SEO jobs.

all the best,

 

For best results, 301 redirect EACH page on the site though, not just the homepage.

 

First, the interchanging the keyword placement (detroitwidgets.com & widgetsdetroit.com) will have no significant effect on ranking. For these type of keyword, if you search adword keywrod tool then Google show same search volume , it show that Google know that there is no difference between both unless it is long trail keyword or phrase.
You client may be thinking that people might try to type directly detroitwidgets.com than widgetsdetroit.com , so expecting more direct traffic. This is the only benefit I a seeing.

If it change then it will affect current ranking and traffic. However ranking for keyword that is in domain is not a big issue if competition is moderate.
You can also suggest him to redirect new domain to old one and use URL masking if feel comfortable.