I first have to that Leo at
http://www.rlengines.com/ in conjunction with Turbocam which performed an Optical Emission Spectroscopy, I will add Leo has been working on a new anti-wear treatment TX-1 for performance components
http://www.rlengines.com/tech/TX1.pdf Guive him a call for more info.
Some of the Key ingredients in cast iron to make it strong are Nickel,Molybdenum, Copper
The Little-M nickel content is 0.149, Molybdenum 0.211, Copper 0.404
Dart SHP Nickel content is 0.071, Molybdenum .016, copper 0.283
Chinese block Nickel content is 0.005, Molybdenum 0.005, Copper 0.020
Leo did the Brinell test by using the Rockwell B Scale and converting it to Brinell scale and he will back this test.
Little-M tested 200
SHP 190
Chinese block 107
I am sure the chinese blocks will very from block to block and now I see why when I had to line hone the chinese block it kept loading the stones up as it was extremely soft.