I recently purchased a 1948 Cadillac that has this engine in it. The best I could come up with is that it may be a 1965 425 out of a starfire. But I may be wrong. My wife tells me that all the time. There is an "A" in the engine block casting on the front of the engine near the water pump. The heads have a "N" in the stamped smooth pad. The heads appear to have removed at some time. The paint is gone on them and there is some sealer showing. The engine color appears to be original, as well as the color of the air cleaner. I have looked at a Gazillion photos online but have not found an exact copy of my engine. I am a ittle confused on the correct routing of the crankcase vacuum lines. I have a breather opening on each valve cover, one is marked PVC and the other is marked PIPE. There is also a broken rubber grommet on the air cleaner snout. I assume the one from the aircleaner attaches to the grommet which is marked PIPE. I have seen that in pictures. I do not have the correct breather filter for the valve cover nor do I know which one is the correct one to purchase. I think if I could get some help on Identifying the engine, I would be able to get these line correctly installed. Attached are pics of the aircleaner and the engine. Any help would be appreciated. -fisher http://s115.photobucket.com/albums/n286/longboardguy/1965%20425/