.

 

those studs are threaded on. when you buy a new water pump they come with new ones. If you decided to repalce the water pump they are cheap, I think my new one was about 25$. But if its good you are i no way sol. Just figure a way to get it out and you can replace the studs.

 

Yeah Patrickgraven's right they are studs.Try to drill it out without buggering the threads.

 

short 10mm

 

i dont see why 3 studs would be a problem

But if you just drill/ knock out the stud you can just run a nut and bolt and be fine, Its not like they balance the pulley off the water pump.