I have a NOS dipstick with a tag on it that reads B5S-6750-B which means it is one for a 1955-1957 Ford Thunderbird. It has the number ECD-6750-B stamped in the side of the dipstick itself. I can't find what this number means. Can anyone help me with that? Also, why is the dipstick unique to the T-Bird engine? Is the oil pan different from a 1957 sedan 312 engine? I guess what I really need to know is, will this T-Bird dipstick give an accurate oil level reading in a 1957 sedan 312 c.i. engine? Or, are the dipstick tubes themselves of a different diameter with the stick not even being able to go in the sedan tube? So many questions to show my ignorance, but that is why I appreciate the people on this forum who provide answers without passing judgment. Many thanks!