remember, DON'T thread it in ALL THE WAY! I learned the hard way and had to take the head off, then had to get the thread portion out which broke off flush with the head..needless to say, not fun..
I just replaced this about 2 months ago. If I remember correctly, I read that the best way to do it is to make it as hand tight as possible, then just a 1/4 turn with the socket. Im sure youll know right away if it wasn't tight enough once it hits the water.