First start ideas

[79 Camaro]

Depending on how you plumbed the steam line (plumbed into the top of the water pump) you may have to do some purging after startup. I like using the coolant temp sensor. Just loosen it up slightly and let it burb some coolant out. I use 50- 50 anti-freeze water mix.
Power steering pump? If the system is dry I over fill the resevior slightly and then check the level when you can turn the wheels back and forth as suggested above.
I done a number LS swaps, both new engines and used and I've never primed the engine oil. Never had a problem. On the first start I pull the 12 volt fuse to the fuel pump, crank it a few times to get the oil moving. Then replace the fuse and start it. Not to say you can't prime it but I haven't. If you haven't done a LS swap before you will be shocked how quickly it will start and run.
Good Luck.