I have both a 3800 and a 6400, and I think the original brake lines are the same with the exception of the line going to the rear axle, it will need to be about 2' longer.
If you have problems kinking brake lines get a good bender. I too get frustrated making lines, but only because I bend them in the wrong place, not because they kink.. If you just admit before hand it will take a few tries the whole process goes smoother.
Grigg
