In general , tuna popping rod are longer than 8' in length , I have 3 rods which I use for tuna popping and they are 8'6" , 8'7" n 9'2" in lengths , rated between PE 4 to PE 8 . No one dispute one can use GT popping rod for tuna , as long as one can reach the casting distance .
Tuna popping rod should be able to cast light lures , in my fishing area sometimes to entice a strike we must use light metal jig down to 30 gr. , luckily when the tunas are so choosy the casting distance is not far so we can still reach the target .
For tuna under 25 kg , my favourite rod is HL TN87 with PE4 line in the spool but for bigger tunas , I will use other rods such as LR86 with PE6 line in the spool , these rods mentioned will handle GT fishing too .
Several other rods worth looking are DJ83ML n TBL80/20RF for smaller tunas and DJ83MH n TBL80/30RF SHP for bigger tunas , the choise of rod always come down to personal's way on how to cast , I prefer the stiffer blanks while others prefer the more parabolic actioned blanks .
Regards : Jon .