1. 2. 3. 4. Here's the series of events based on your explanations:
Your engine overheated and pegged the needle, and you kept driving it like that for ten minutes.
After shutting it off and trying to restart, it wouldn't.
Once you did get the engine restarted, it has a bad sound where it didn't before.
After replacing the bad head gasket(s), the engine still makes bad sounds.

Responses to your quotes above:
1. Yes you overheated the engine. Without being there I can't say what you meant by "no sign of response when trying to restart". If you meant the engine wouldn't turn over, then you "seized" it.
2. Makes sense based on what happened in #1.
3. A bad head gasket, but with serious side effects.
4. That milky oil was also in the oil pan, meaning it's likely that it did bearing damage, and possibly ring damage from the engine seizing, which explains the noisy nasty knocking engine I hear in the video.

 

Man I need to read these posts better, I assume after finding the milky oil he had just replaced the motor. Dude sorry all the work was for nothing. As Camaro69 said that motor is done for. I would be very surprised if it made it 1000 mile before a rod bearing spun and seizes the motor.

Antifreeze in the oil is a death sentence for a motor. When put under high pressure the antifreeze turns into an acid and wipes out the bearings. Motors don’t come back for that, not even new ones.

 

Thanks guys. Yes if only I got the news early, i would have saved up maybe for an LSx. The motor keeps having a burning smell and the oil gets milky after changing. Here is a vid after replacing the heater hoses... My plan is to buy a new motor since its done for. Thanks for the input anyways.

 

Man, I'd be interested in tearing that engine apart just to see what happened. I'm hearing a sawing sound, which could be a spun bearing. Can't tell from here though from where the sound is coming from (top or bottom end). Sorry for your loss!