You should know even before the engine ever runs, as usually the blocks fails the 90 lb pass almost immediately. The biggest problem is paying the $250+ dollars for the head gasket kit again when it does.
Yeah, in my two instances, I couldn't even reach 90ft/lbs on the torque wrench before the threads let go. You can tell if it feels right or not.
I finally got it back together almost 3 years later. I installed the reconditioned heads with the old gaskets to test the bolts. All were OK. Then I reinstalled the heads with new gaskets. It runs well except for the "main thump" which is now what I'm working on. I have driven it 8,000 miles and it gets 26 mpg at 65. I have the pan off and everthing looks like new.There is no sign that it was ever full of water. I didn't drive the car until the intake gasket failure so I don't know when the thump started. Never did find out where the braided ground wire on the alternator was supposed to connect.