Am I missing something?!

[hbf]

I did an oil change on my 1973 911T CIS today. New oil filter too. Manual says it needs 8 liters. I have put in 9 liters but the oil level does not even register on the dip stick. I did the usual thing - checked level once the engine was warm and at idle. What am I missing? Do different models have different length dip sticks? The one in my car is 25cm - 10 inches - long. Is it the correct item for the car?

Usually when I do an oil change I simply fill until the level registers. Today I paid attention because that is all the oil I had.

I would like to know what's going on.

[rwest]

Do you have an external oil cooler? That could make a difference.

[Flat6pac]

I always look at 11 quarts on an oil change.
Your dip stick should be stamped with a 911 part number.
The external size of the tanks didn't change through Carrera.
Bruce