Gainward isn't well known GPU maker and i don't expect them to produce issue free GPUs. Looking a bit around the net and i saw quite a few people who's Gainward GPU also ran on the hotter side. Then again, with cheaper GPU than from big boys (e.g Asus, MSI), there's not much else to expect either.
Like i said above, your temps will do for now, but barely. GTX 1060 can do up to 85°C. If you want to get temps lower there are 3x things you could do:
1) With 3x 120mm intake and 1x 120mm exhaust, what you have is very high positive pressure inside the case. Positive pressure, while better to keep dust intake lower than negative pressure, doesn't cool the PC components that well either. With positive pressure, you can have stagnant air which leads to higher internal temperatures since there aren't enough fans removing the heated air from the inside of the case.
To fix that, you're looking towards new PC case which also has top fan mounts for additional exhaust fans. Since with more exhaust fans, you can get neutral or even negative pressure. While negative pressure has highest dust intake, it also cools the best since hot air is removed as soon as it's generated. Also, negative pressure works with natural convection and is good to cool open-air type GPUs.
Oh, solid front panel cases (like yours) will have frontal airflow handicapped compared to the mesh front panel case. So, if you want best cooling, avoid cases with solid front panel.
2) Increase the speed of your current fans (e.g max speed) to get more air passing through your system.
Though, that does increase the already high positive pressure even more and depending on the fans you use, they may not be good even at max speed. Replacing fans can have huge benefit if your current fans are for the eyecandy and not cooling performance. For a good airflow fan, look towards Noctua, Corsair ML Pro LED and NZXT AER RGB fans.
3) Replace the GPU.
While it would be pointless to get another GTX 1060 just to get lower temps, you can look towards RTX 1660 Ti or above for additional performance. As far as brand and model goes, MSI Gaming X series GPUs are one of the best out there when it comes to cooling and silent operation (they also cost accordingly).