Having 5 Kimbers, I have made the following changes on each:
* Changed thumb safety for a standard Colt commercial unit,
* Checkered front strap; tape, stippling, stupid wrap around grips are cheap, tacky and make the gun feel like a
pachyderm's penis,
* Changed out the full length rod for a standard commercial or mil-spec unit. If it makes you feel better, you can put
a closed recoil spring plug in,
* Keep the plastic main spring housing and spend your money elsewhere, the plastic ones last for ever if you don't try
to cook them.
Enjoy your Kimber as it is a fine gun and I have found mine to be ultra reliable and accurate. A couple things you might want to do; throat the barrel if you are going to shoot cast. Some of the newer guns don't have much throat if any and cast can hang out of battery. Get Wilson mags for extras.