How do I identify my transmission?

[McCarley]

I have a 1994 GMC 1500 Kingcab 2WD 5.7 - There are 2 options for my transmission - how do I know which one I have?

 

4L60E

 

or

 

4L80E

 

What I do know is that it is a shallow pan with 16 bolts (filter kit).

 

Thanks in advance.

[Nick99Chevy]

1/2 tons only come with 4L60E. Should be RPO M30 in the glovebox also.