Machias,
I will be up there at the same time as you. I put 4 lb test on a backpacking spinning pole. We also have a fly rod we are taking.
I used to guide up in the tribs of the Susitna and there were grayling there, pick up a few spinners from size 00,0 and 2. I found that a meps with a rooster tail seemed to work the best for me.
I'm headed up with Brushcrawler on the 26th. We will be around for 10 days.