This is the cutting tool kit used to machine Caterpillar C-15 blocks to install brass water repair inserts where the rubber grommets sit on the block. 
This process can be done with the block in chassis or in the shop by using a magnetic base drill. I’ve done well over 100 blocks with great success.
Set the depth on your mag drill, the cutter will pilot off the original water hole. Plunge down into the block and the inserts are then press fit into the block. 
Kit Includes:
1 - Cutter
1 - Reamer 5/8”
1 - Install Tool
24 - Brass Inserts ( Std. Size )
2 - Brass Inserts ( +.005  O.D. )
2 - Brass Inserts ( +.035 Depth )
Custom size depth and O.D brass inserts are available if needed.
The cutting tool will do quite a few blocks ( if used properly ) before needing to be re-sharpened. 
$125.00 charge to re-sharpen 
Brass water repair inserts sold separately