More Bridgport lube questions.

Hi All,
Could someone look at this link to picts of my Series II head:

http://www.users.qwest.net/~indigo_red/files/PIC0010.JPG

Question, is this the spindle oil fill plug, and if it is, do I
fill it till its even with the plug?
(i.e. as in a auto rear-end)

Thanks,
Lee