Advice for Cracked Block

[YourBuddy'sTruck]

I'm hoping for some knowledge and advice.
My Dad has a '72 C10 that he bought a Crate 350 Engine to power it.
This was about a year ago now that he installed it.
Set in place and added break in oil, fired up and ran great for about 20 minutes.
At that point he shut it down to finish up work on the rest of the drive train, as in the transmission and rear end.

Then life got in the way and the Old Man fought of some heart problems, kicked back hard at some lung cancer, and finally with a pacemaker, he's feeling 72 yrs old again.

So he gets back to his truck and fires it up for about 20 minutes and says it's running really rough.
Decides to drain and replace the oil....and water comes flowing out.
He asks me and I'm thinking the Head Gasket or Intake Gaskets were poorly installed.
So he pulled the intake and it looked fine. He pulled the Head and 2, 4, 6, and 8 Cylinders are all full of water.
As he tells me of this, I think something is wrong, so I go over to look at it myself and I find the Block to have a substantial crack in it on the Driver Side.
See Photos....

Questions are:
Is there any way my Dad caused this?
Seams to be it was sent to him this way?
What would cause a crack like this anyway?
What would you do if this was your situation?

Please keep in mind that my Dad is not a professional mechanic, but I have personally witnessed the man assemble a basket case Shovel Head in his day.
Thanks for any advice in this matter.