You mean the one that bolts to the transmission?
I am pretty sure that 1G front motor mount inserts are the same size as the 2G rears (i.e. 2.78" diameter by 1.5" wide). I have never used a 2G front engine mount, so I don't know about that one.
I know this isn't very helpful, but what I am saying is even though the pictures look the same, I'm pretty sure if you buy a 'set', then 1G motor mount and 2G motor mount dimensions are going to be different.