help id this trans/transfercase

[biggsteve97]

I do not believe there is a tag however GM used to stamp 4L80 in the bell-housings if it is not a removable bell-housing. If it is a 4L80E it does not look much different on the outside than most of GM's automatics, if it is the Allison the trans is large in comparison to any GM automatic and it will have Allison stamped in the side as well as an external spin on filter next to the pan at what would be the drivers side front corner if the trans was in the truck. These are the only two automatics GM used with the transfercase.