I removed the subframe on my 68.
Removed engine and gear box.
Had to pull the gearbox out of the engine. Never did it before so I just pulled the Gearbox and left the convertor on the engine.
Did that using a shop crane so I pulled it straight and it went out smoothly.
Since then, I learned that I may have damaged the seal (which will be replaced) and the pump.
How can I tell if there is anything wrong there before I put it back in place?

 

The only way to be 100% sure is to pull the front pump and inspect it for damage. If it came out straight and smooth it should be ok. If the weight of the transmission was hanging on the converter it is possible that you could mar the inside of the pump and cause metal into the hydraulic side of the trans. This is pretty rare to happen. If you have never done this before I would say there is more chance you would screw up the process or you would miss spotting the damage anyways then there is any damaged to the pump. I sure you know in all future removals leave the converter in the trans while it is being removed.

Where you need to be careful is putting the trans back in. The converter must be removed from the motor and slide into place. I would suggest watching a you tube video on it. If you do not get it right you will need a new front pump and a rebuild.

 

Thank you for the reply.
Before removing the gear box I asked a Facebook Camaro group and beside the usuals "leave it to those that knows" useless replies, nobody said anything.
So as it seems to be easy I carry on and only later I learned that the convertor was to remain on the gear box.
Since then I watched some videos so 'I know".
Right now everything is in pieces.

Do I need to fill some transmission oil into the convertor before sliding it back on the gear box? (Not talking about oiling the shaft...)

 

Yes it is best to fill the converters, that is less time the pump will spend filling the converter and rotating parts that are low on oil. It can get messy. There is no reason to to fill it completely as half of that will end up on the floor. If you know the converters capacity add about half. Usually the best you can do is fill the lower half. You will be playing with it to make sure it fully seated and everything above half way full will end up on the floor.

In the end you want to listen to make sure if clicks in place. For beginner I tell them to get out a tape measure and make sure the distance from the front face of the converter is inside the front face of the transmission MORE then the flex plate is sticking out past the back of the engine. Before you bolt the converter to the flex plate the converter should spin freely. The you should need to pull it forward to meet the flex plate and tighten the bolts.

I know I am beating this dead horse but this is the biggest most common mistake new guys doing the first install make and it is an expensive one.