Trying to install Corporate2 - 1.6 but have custom 404 pages

Greetings.
My site is currently live using Corporate2 1.5

I am trying to install Corporate2 1.6 in a separate folder so I can move content and test it while my current site is live.

However, I setup a custom 404 page and when I try and open the new Joomla folder where Joomla 1.6 is located, I get a 404 error. For instance http://www.site.com/NewJoomla

Do you know how I can install the new template with this configuration?

Thanks.

All right. I think I figured it out.

Assuming I can have multiple versions of Joomla running without a problem . . ..

If I go through my web hosts admin site, I can access the folder directly and "preview" the index.php file from within the new Joomla16 install folder. This starts the installation process in the browser.

Is there anything else that I should keep in mind when I install or build my new Joomla 1.6 version of my live site?

Thanks.