Ill do that. Thanks Warren

Where did you get this used engine?

I bought it in Sacramento, CA

After I got the torque converter out, there is oil coming out on the center of the converter. Is this oil is separate from the transmission? Do I have to replenish the oil? There is plug on the side of the torque converter. Is this the plug where you pour oil? Please guide me.

That's transmission fluid. Put the TC back on the trans and make sure it engages the pump. Do this by rotating the TC until it slips into the trans another 10-15mm. After you get everything back together and the engine running, fill the trans with the proper fluid through the dipstick tube.
Why did you pull the TC out of the trans?

The TC wont come out when I pulled the transmission away from the engine. The TC was left intact to the engine. I have to apply a little force to get it out. Nothing damaged. Now I am ready to attach the transmission to the new engine.
Regarding transmission oil, the manual calls for a ATF III. Is this the same as ATF+3?
Which is better the regular transmission fluid or the Mobil 1 ATF full synthetic.
Thank you Chas

The TC is bolted to the drive plate. You should unbolt the TC from the drive plate and keep it stuck in the trans. Since you didn't do this, I suggest you replace the TC seal in the trans as there is a good chance it's damaged.

Most of your ATF resides in the torque converter - it is a fluid coupling. You drain it from the drain plug, and can refill from there too, but obviously check level again after everything is all back together, and don't let the engine run for long at all until level is back to where it should be.
The fluid you want is Dexron III. I don't know if you'll get much benefit from the synthetic - just change it as sepcified (every 30k or so if I remember right).