Ranking 2 Domains in different Country

Hi, we have one website which is ranking very well in Australia with a .com.au domain - 60DR, 1500 monthly traffic. We want to expand the business across to America and we are planning to launch .com domain.

Will it be sufficient to replicate the exact website and launch it as .com domain but change:
- Meta data for main top visited pages
- Remove any local traces from .com.au domain and use America’s eg: address, phone numbers
- Change the spellings, grammar accordingly to American English

The website has at least 240 blog posts so they will be replicated as they are, 10 services pages which will be changed according to above. The overall content will not be re written like any paragraph or such.

Will this be a duplicate issue? any content penalty? and would this be a good way to approach this solution? If not, please suggest any methods to approach this so it can rank in America. Any help would be grateful for. Thanks!

I would suggest moving everything to the .com domain and potentially using sub-domains such as /au/ and /USA/. You can then use language tags to essentially tell Google that page A on /USA/ and page A on /au/ are the same in content but intended for different regions to get around the duplicate content.