cromag
you might be running into the % of a % issue
The book had a 'tight' line spacing specified (might be compensating for a system font)
You don't have that over-spaced font font now, so things get smooshed and 120% is not enough to overcome the base.
Personally: I have a 'clip' of my default 'body (class)' css that I replace in the CSS using an editor
is one of the lines