It's time for a quick note on reluctor wheels. All engines shipped from GM since January 2006 carry the newer 58x reluctor wheel. If you have an early LS2 (PN 12499750), then it's considered an '05 engine and will carry the 24x reluctor wheel like the LS1 and LS6 variants. This is important to know when you start shopping around for a computer to run your engine. Any LS engine can be converted either way by swapping out the reluctor wheel, but it's a bit of a pain since it has to be pressed onto the crank using a special jig. The easiest way to tell from the outside is by looking at the crank trigger (located near the starter): grey for 58x and black for 24x.