How would you convert 200 html pages to php? There's a catch.

I do not want to lose any ranks, receive any penalties due to duplicate content etc. But I would like to make use of php and the additional benefits it provides.

Do I change the files to php and use .htaccess to convert all the php files to html again? From what I understand nothing would have changed from the search engines perspective. I'd have php benefits, and wont lose my html page ranks etc.

Do I change the files to php and perm redirect all old html to their new corresponding php pages?

I have been wanting to do this for a while, so looking for some tips or a option C? Did I miss something else possibly?

 

Why not configure your htaccess to parse all html file like php and then add the php feature you need in each files ?

I guess this would be the code:

 

That's what I would do.

 

From what I understand, the links will not be broken.
I'll try this on a test domain this weekend.
If something breaks I'll be back .
Thanks for the help.