Domain change: redirect to index, or to old content on new domain?

[sbook]

Dear All,
Please help me with domain redirect. We are changing the domain and have 2 options for redirect.

1st is to the related active website(have 0 backlinks, but ranks good in G). Content is related but different, all redirects would go to index.

2nd to new domain, on the same old website content.

I cannot set 'domain change' in WMT due to some reasons.
If i choose 1st option, i don't want to loose rankings of both domains.

[phranque]

all redirects would go to index

don't.

google might see this as a soft 404 error:
http://support.google.com/webmasters/answer/181708?hl=en [support.google.com]


http://googlewebmastercentral.blogspot.com/2008/04/best-practices-when-moving-your-site.html [googlewebmastercentral.blogspot.com]:

Don't do a blanket redirect directing all traffic from your old site to your new home page.This will avoid 404 errors, but it's not a good user experience.