Kix - that is one job that has been waiting far too long. I use King's drop-in beavertail grip safeties, and they simply replace the existing grip safety.
Savage is right in that most 'drop-in' parts drop right into your parts box but the two King's beavertail safeties I 'dropped' into both my Colt Commander and my Springfield Gov't Model are both still there, function perfectly and do not bite the hand that feeds the gun..........
Williamlayton - that is not always true. I once picked up a bent driver that had been whacked against a tree and that darn thing put those golf balls right where I wanted them. Maybe some drivers just need to be, umm, tweaked....................
Kix - we have a poster here named SharonAnne and she is probably the most knowledgeable of all of us when it comes to setting up 1911s for competition and making certain they function perfectly without biting the hand that feeds her pistols. She has written some very well detailed and instructive posts regarding parts and proper installation. Follow some of the threads on this forum by SharonAnne and you should see tons of great information. HTH. Mikey.