Originally Posted by ccrobin

Hmm, well it is how I have always lapped parts. I apologize if my definition isn't proper. Here is what Wikipedia has to say about lapping: Lapping - Wikipedia, the free encyclopedia

Yes, 2000 grit is all I used. You won't likely find it at Home Depot, but any decent automotive store will carry it (usually used for body/paint work). It only took about 20 seconds for each surface cleaned. You want to be careful not to take more off than needed, as thinning the metal will lower the tension on the spring and could actually lower the pop pressure of the injector if you get too aggressive. Using 600 grit only will actually leave the surfaces too rough, and will likely leak.