Quote:

Get a cooling system pressure tester and pump it up.

Yes, with it good & hot pump it up to 15 lbs & let it sit (overnight if need be) & monitor the pressure drop & post your results. You'll likely see a drop in minutes. Yes it might be a crack in the block. did they pressure check & magnaflux the heads when they did them? Did they check the block deck(s) with a straight edge?

live every 24 hour block of time like it's your last day on earth