Dear,
I just decided to use GNU Coding Standards for my program. So I will have to change lots more than 10000 lines of code.
Maybe I'm wrong but I didn't find anything about the maximal length of a line. In the CodingStyle of the kernel, it's the chapter 2 "Breaking long lines and strings" : "The limit on the length of lines is 80 columns and this is a strongly preferred limit". They write a specific chapter about this problem (and I find it very useful and understandable) but the GNU Coding Standards don't speak about it. I don't understand why.
I think it could be a good idea to have a little speech about it. I have to be honest, 80 is really small now we can have a 1080p screen but I easily understand it for console screen.