Ok, listen, This is my case
I have a 1984 z28 and it has problems

Number 1: It gets hot and I dont know why, when i stop the car after driving it a few miles the engine coolant is usually boiling out of the resevoir.
The Story: I was driving my car out in the country and it decides it's gonna start smoking antifreeze, that's when i realized, hey the car's getting pretty hot. The engine gets to clattering and i stop the car (After it dies). It's piping hot and i cant see a thing because i just swapped the hood and didnt put the light in it. Turns out the radiator cap popped off while i was driving it and all of the engine coolant is spewing out all over the engine. I take it to a guys house about a hundred feet away and we stick a hose in the radiator while it's running to cool it down. Finally we get it cooled down and we put some water in the resevoir for good measure. I drive it a couple of miles down the road to my girlfriends house and park it and she takes me home. When i parked it, the water was boiling and rushing into the resevoir. I let it cool for awhile and came back with my brother. I then start it up and put more water into the resevoir and drive it the 5 miles back home where I park it and it steams and boils some more. I wait until the morning before i drive it 5 more miles to my grandparents house and park it. Now a couple of days after all of this, I messed around in the engine and i drove it home, it didnt overheat this time, but it was still boiling out of the resevoir. I dont know what the problem is, I think it might be the water pump, but i could never know. Somebody for the love of pete help me!!

 

If it started "clattering" as you say you may have done some real damage. Either the system is not holding pressure or the stat and/or water pump has a problem. First, look in the oil for signs of coolant. Oil will get a milky look with coolant in it. If thats OK then simply troubleshoot the cooling system. If the cap was loose and you refilled it maybe there is air in the system, try bleeding it. Otherwise simple troubleshooting of the cooling system should reveal the problem.

 

during all this when you were adding water, were you adding any antifreeze also?

MD350
89 Formula 350

 

there is coolant mixed with the oil, and we've discovered the problem, and it's worse than i had figured, blown head gasket, looks like i'll be getting a new engine, maybe a 350?

 

Don't overlook a blown intake manifold gasket, it does the same thing and it's a lot easier to fix.