Mika I had to replace my water pump also on my 90. Mine started out as a small leak and toward the end it turned into a raging flood gushing out. Check with a mirror to see if coolant is leaking out of the hole on the underside of the pump.
I got my pump from corvette central with gasket for $199.
I decided to go with Samco hoses. Im still waiting on the hoses. They wont be here till june when the temperature will be 104 degrees 85% humidity. I just can't wait.