Sorry for the slow response, was kinda busy.
I did however take a wild gamble after remembering a post I saw a while back mentioning that if unlucky, the block might not be properly flat.
So I went and bought a new cpu block and quickly installed it today (the xc7 again of course, need the aesthetic of using the same brand)
And now the max temp it reaches is 70-75c when running the torture test in Prime95 (mind you the room temp is around 27c). I do still see a little bit of spiking, but not in the same way.
I also checked the bios, and it is running with MCE on.
I can also see that the package is reaching a max of 150w in CPUID, which also suggests it has been overclocked.
All in all I think it's pretty acceptable. Might try reducing the voltage and see if that will make the temps better whilst still running stable.
And thanks a ton for the help guys, I appreciate it.