Hi,
If you Google Ulua and Hawaii, you should come up with a forum that specializes in shore casting or Whipping for GT's. I used to cast for them back in the 80's, North Point, Big Island. Brings back great memories! Back then, me and a bunch of local boys were using 9-10 ft rods in the 20-30 lbs class, but back then, those "Reef Trolls" were much bigger. From what I heard, most of the shore caught GT's are much smaller 3-7 kg. Check out that Ulua forum, I'm sure they will give you updated information. Good Luck!
Ed