Is there a SA 1911 GI mil spec and 1911 A1 GI.mil shpec?.

[BUGUDY]

I am looking at GB and seeing a 1911 A1 GI mil spec , but I can't find a GI mil spec 1911 A1 in the 08 Firearms book. I find the 1911 GI mil spec, and I find a 1911A1 mil spec. I would like to buy a SA, in the 500$ range, but I want to know what I am getting exactly. Thanks

 

[j1979]

Strait from the SA website. Explains the differences. They can both be had for in the 500 range.
G.I. http://www.springfield-armory.com/armory.php?model=6
Mil Spec http://www.springfield-armory.com/armory.php?model=7