If one of the lines of a paragraph is shorter than the rest, it will have larger spaces between words. Your options seem to be:
- Track the letters of the words in the paragraph so that they are farther apart, which will lessen the space between words.
- Play with the character width.
- Recompose the words so that they fit better.
- Something else that I haven't thought of, but you'll find out when someone else replies.
Of those, I'm not sure that 1 or 2 would look much better than what you already have. Maybe consider justifying all but the last line.
Make sure your text is just the same word repeated over and over...
Other than that, no. That's the nature of justified text - the spaces (letter or word, but mostly word) are adjusted to fill out the line. You could play with the hyphenation and justification setting, maybe adding a little letter spacing, reducing the word spacing or even using glyph scaling, but you're very unlikely to achieve what you want, have it look good and be comfortable to read.
Replace all regular spaces with a "Non-Breaking Space (Fixed Width)" followed by a Discretionary Line Break.
I strongly advise to not do this. The only place left to justify the text, then, is in the letter spacing, and this will vary wildly from one line to the next. It is true that the same happens with the regular, common, accepted way of justifying text by varying space width, but since text is read per word, and not per letter, inconsistent spacing between words is more acceptable and less conspicuous than inconsistent spacing within each word.
Do not do this. It is not an acceptable way to get your "perfect 'block' of text".