Being a 2006, the oil lines you currently have are external and so will the S&S crate motor. It was never an option to have internal oil lines on 2006 models. Also there is no drilling or tapping required on the S&S crate motor for 2006 models. It is a very simple installation and no machining of any kind whatsoever is required. If you can change your plugs and wires you can install the oil line kit on the 2006 and earlier models. All that's required is removing the drain plug from the oil pan, the allen bolt right next to the oil drain plug from the pan and there is an Allen bolt that screws a small block that two fittings screw into on the bottom side of the case behind the flywheel compartment and then just slipping the two hoses on and putting the hose clamps on them. People freak out over the external oil lines on the 07 later applications. It does not apply to you since yours is earlier than 2007. I don't understand what all the fuss about the external lines on the 07 later motors is about. Harley's have had external oil lines for years. All the way up until 2007 in fact and I don't recall ever reading a single post where it's cause any problems but for whatever it's worth, the 07 later S&S cases that so require the external oil line kit where the SE cases did/do not, the S&S cases are WAY beefier and would be my choice between the two if you really wanted to push the envelope of what one of these motors are capable of and as of last week, I was told there were only two sets of SE cases left and when those were gone there would be no more made with SE cases. Far as I'm aware of, the 2006 earlier S&S 124's were never available with anything but S&S cases and again, I've never heard of a failure yet even on early bikes that never had internal oil lines failing because of an external line problem. I'm sure it's happened but how many pre 2007 bikes are out there and how many miles have been logged vs how many you've seen or heard of failing?? Classic example of the Internet making a mountain out of a mole hill IMO.