Notes- the lower O-ring was stuck in the bore of the fuel manifold. Need to remove it. The new injector has two o-rings on it. These are bottom feed injectors. When you remove injector without removing fuel pressure regulator, the fuel in the manifold will drain into the intake and into the cylinders. Could cause hydrostatic lockup which can cause engine damage. You will need to remove regulator before removing injector so that the fuel can drain from the manifold. You might even take a blow gun and blow fuel out of manifold passage where regulator mounts. Or if you don't remove regulator, you can remove spark plugs and crank engine to blow the fuel out of the cylinder. If you do it this way, you might even want to change the oil, which I did. Because fuel could seep past piston rings and into the the oil.