Go to a parts store and get the Oring kit, comes with two for each injector(one for the rail side, one for the head side) and orings for the Pressure regulator at the front of the rail. Like $10 if I remember correctly...It was recommended that i lube them a little, so i just used a little oil on the end of my finger and rubbed it on. No leaks at all, I did all new injectors last november or so...
Cory