best line for a 16 foot 8- 9 4 pice Jim Geen rod

Keep in mind that Jim Green still makes custom and experimental blanks and rods for some of those folks he knows well. I have seen several on the Skagit and Sauk, including a few with the guides and grips taped on. These rods were from 12 1/2 feet to 16 feet long. All were for lighter lines, 6/7, 7/8, and 8/9. And all were within the last 4 years. Also, the guys who had them fish custom shooting heads of 42 to 47 feet including sink tips, or Windcutters, not long belly lines. This needs to be taken into consideration as well.

This said, I would start with a 7/8/9 Windcutter. If this is overloading the rod, go down a size to the 6/7/8 Windcutter. YOu could also make yourself a custom head by splicing turning a 10 weight shooting taper around (front taper is spliced to running line0 and which is cut at 20 feet. To this is spliced 12 feet of 9 weight line. Finally you put a loop on the end of the piece of 9 weight and then loop 15 foot tips of 9 wieght to it. This is basically the set up that thefolks were using that i have run acros with these prototype customs on the river.