Just thought some of the other 2001 model Springfield owners would like to know that if you intend on replacing the ILS mainspring housing there are a couple of extra parts needed.The ILS doesn't have a mainspring cap pin like all other 1911 style pistols and the mainspring cap has a deeper pocket than the standard issue part.If you use the Springfield cap in a standard mainspring housing you can cock the hammer but it loses force about half way through its cycle.The missing pin was obvious when I went to install an Ed Brown Maxiwell but the mainspring cap wasn't.Hope this helps anyone who may be planning on replacing the ILS.
Shooter Ready?