I have a set of GPa pros Ntec. Used 1 session at Barber. Took them off to street ride this summer and only track the actual track bike. I thought these tires were incredibly sticky and performed great..my opinion of course. $220+ shipping (I may be able to get a good rate thru work) retails $378 and up for us non sponsored folks.
Did you buy these at a motoamerica race? Those stickers indicate that. And if you are a motoamerica racer, your ten laps are different from most everyone else's lol.
Build dates, compound(hard 8477, med 7455, soft 2662) and how they were stored might help. You're location as well, might have someone local want them. Steve
Sorry heres the info: I bought these off a racer new as im a trackdayer only in 2015. They are both Med compound and dates are May 2014. I threw these on my street bike for a session once done I decided to stick with tracking my little bike. They were then removed and they have always been stored indoors (basement) upright off the ground. Location: South East MI