I just got my 1987 IROC back last night after a year of being restored (painted, rust removed, etc.). When it was started and rolled off the trailer, I did not notice anything (it was only started for less than 1 minute). I did notice a small pool of anti-freeze when I moved it into the garage. Then I started it today and let it warm up and it started steaming like crazy. I really don't know much about this kind of thing. The oil looks good (not milky at all). I am wondering if anybody might be able to guess on which gasket might be the issue based on what you are seeing in the video:
I am pretty frustrated to get the thing back and have to deal with this, especially considering the amount of money I spent. I just hope the block is not cracked. It is the original 350 and I had planned to rebuild it when it crapped out.

UPDATE: It was actually the heater control valve that failed. A common problem and easy to fix.

 

The hoses with arrows, and the round black plastic valve, and a few hoses that can't be seen underneath all carry coolant for your heater core. I'd start by inspecting them for leaks. Get right in there...run your hands over the length of them (when the engine cools).

 

Thanks, I will try that. If it is a hose leaking, it is leaking right near the back of the valve cover. To make things stranger, I went back out to the car, started it up again to really let it warm up, and it steamed like this until the car got to about 200 degrees, and then it stopped steaming. Plenty of fluid in the radiator. I am guessing something might have swelled shut? No idea at this point. I might try to get some better video of the spot I see it dripping around.

 

Probably intake manifold gaskets. If it's not a hose.

GD

 

Probably a hose

 

Id say its the hard lines down by the passenger frame rail.You can kinda see steam down there, plus there is steam coming out from the fender side of the blower fan.

 

 

my guess is it's leaking at the coupling where the heater hose enters the firewall.