I don't know what rods and drag you fish, but you may or may not run into problems of shockload explosions with pe6.
I fish lighter and just for yellowtail kingfish which mostly don't hit as hard as GT do. Still with a lighter pe4-6 rod and top quality pe4 I had it explode on the initial run with too much screwed down drag. Happened plenty of times on even lighter gear pushed to the max, but bringing a knife to a gunfight, this is to be expected.
The same will sometimes happen if you do the equivalent one level up with pe6 on a (true) pe8 rod with max drag.
I hear from the experienced guys that shockload is one of the most important factors fishing for big GT.