waterblock flatness...

[the monk]

hello everyone, i am new here and this is my first post and water cooling project. i started a danger den torture rack. i have read about lapping cpu's and heatsinks before. i have been a machinist for 30 years and fully understand about flat plane's, or surfaces. i have a surface plate in my workshop, and checked my blocks i plan on using for my project. one is a danger den, and the other is a EK. nither one was flat. the DD had a male crown, and the EK had a valley in it. in the DD photo you can see the dull "witness mark" i left, on the outside edged or were the dullness is. as i think about i would bet none of the blocks are flat coming from the manufactures. peace, randy.