It's a 1967 deville with 7.0L V8 - all original, that should translate into 429cu in. I read somewhere that it needs like 12.5 quarts total for the engine but i might be wrong. Please correct me if Im wrong.
I see what you're talking about now! The '67s are pre- 425/472 /500 family of engines.I really don't know anything about those engine( I thought you were talking about the '77-'79 425s). Most of us use the '68 -' 79 engines. One thing I do doubt, though, is the use of 12 quarts of oil. That sounds like a lot for any engine. Maybe someone else here can chime in on this engine model. Sorry for the mix up. P.S. There is another forum on this board called "Other Cadillac Engines". Perhaps someone there can help.
12.5 quarts? If you still have the OM, there are fluid specifications in it. But like most automobiles its probably 5 quarts. Put 4 in and see how far that gets you on the dipstick. Make sure you let the oil seep all the way down into the pan before you check the stick.
Also...on the dipstick itself it should say the oil capacity. Mine says "4 Quart Capacity" with a filter change its 5.