Originally Posted by topquark
I need to clarify what I want to achieve. I want to get the same line spacing I used to have with mobi, but using the nicer fonts and style of azw3. I've tried all manner of settings (line spacing=0, minimum line height=0) but could not get the same effect for all azw3 books I have tried.
I have something for you to try. I have a modified font that when used with a KF8 eBook on an eInk Kindle gives tight line spacing. You can use the ALT fonts trick and put this on your Kindle and try it with KF8 eBooks. The link below is to the fonts.