I have a 2000 van with 5.7 350, was running great until I put Anti Freeze in it was really low, I put it in then it started to smoke really bad and would not get out its own way had to have it towed, any thoughts on whats going on, it has 152,000 miles on it

 

Well if the anti-freeze was really low and you didn't see any visible leaks, I would guess you have a blown head gasket... hopefully this didn't cause further damages.

 

Ditto. Running great, but bleeding engine compression into the water jacket and forcing out the coolant. Good thing you caught it this way, you prop saved the heads.

 

Sounds like head gasket to me too.
Eric