Is there a XF86 setup tool for Gentoo that will create modelines?
I can't get the resolution and refresh rate right with the xf86config program that comes with X11.
Actually you don't need a config tool any more. The reason they took it out in X4 is because they usurped it with "X -configure" that command will automatically detect most settings and then you just need to copy the file that results into /etc/X11 and tweak it a little and all is good.