Springfield Question

I'm just getting into 1911s. I have a Springfield Armory 1911-A1 Mil-Spec. I swapped out the spur hammer for a used one off of a Kimber Warrior and the Warrior hammer was hitting the grip safety so I ordered this:http://www.brownells.com/.aspx/pid=1...GH_GRIP_SAFETY from Brownells because it says it fits the SA frame contour. But it doesn't come close to fitting. Can someone help me out on which grip safety to get. Thanks in advance.

A lot of time "drop in" parts don't exactly drop in on a 1911. Have a smith fit it or bust out the file.