440- Engine oil dip stick

Hi,
I have a 440 and I have changed the engine oil dip stick to a Milodon 22070 (lost the one that come with it). Since fitting the engine to my 74 dart I have had to change the sump to a Charlie oil pan due to having an alterkation front end.
I have only just noticed the Milodon dip stick doesn't have any markings on it.
So how do I know how much oil to put in?
Is there anyone I can contact or should I order a different dip stick?

Thanks in advance

Below are links the the sump and my original post.
https://charliesoilpans.com/images/OilPans/Images/Pan14.jpg

(74 dodge dart sump clearance)