The Loop: Insert Content After Specific Post Number

Hello,

I am wondering if there is a way to insert a block of content after a specific post number in my Custom Post Loop.

Essentially, I want to say:

After the 2 most recent mosts, insert this block of code.

If that can be done, I would also be interested in knowing if something like this is achievable:

Start a Custom Post Loop that excludes a specific Post Format (or Category), but after every 2 posts, insert 1 of the excluded Post Formats.

Thanks for any assistance.