Ran it a while and the steam cleared out. My only issue is the motor dies when I get timing to around 12 deg btdc.
As Fierofool posted, you will have to have the ALDL jumpered when you set the timing, or it will be waaaaay off. To the point that it will barely run.
Also... in order to set the IAC properly, after major work has been done, the car will need to be warmed up and driven for a few miles, at speeds of over 35 MPH, or so.
If your steam went away, I'm guessing that it was just water or condensation that had gotten into the exhaust system. Or maybe even oil smoke from when the engine was reassembled. (Just a wild guess, here.) But as long as it runs okay, your oil and coolant stay clean, and it doesn't steam any more, you should be good.