Keenserts are rather large. Caterpillar dealers carry a kit and will sell them. When space is a limiting factor I like to use Rockmount inserts. They are like a keensert but are self tapping & are not as wide.
http://www.rockmountnassau.com/ I didn't see them listed on there web site but I am looking at the kit right now, maybe you could call them.
I'm sure these are metric bolts (haven't pulled my converter yet). You may be able to just tap them to a standard bolt if it's close enough, without even drilling the hole out. just a thought.
If you use red locktite
usually you need to heat the bolts to get it to break loose without yanking threads or breaking the bolt. I personally hate the stuff but it does have its place, just not very many places
.