Hey Flyer, I don't usually give tech advice, I just come here to read and look at hot rod builds. But in your case, I own three LT1 powered vehicles and have a little bit of experience with them.
After looking at your photos and watching your video a few things stand out.
1) You have a big vacuum leak, indicated by the really high idle speed and the throttle stumble. From the photos it appears your PCV system isn't connected properly. It needs to be plumbed properly. You can find some good photos of the component setups on a site called SHBOX.com. He a great guy who built this gold mine of LT1 information.
The PCV valve should be in the drivers side of the intake manifold with a line running to a fitting under the front of the throttle body which supplies the vacuum. I've got a feeling thats where your leak is. That filter you have in the rear of the passenger side valve cover is a no-no because it's also allowing un-metered air(after the mass air flow sensor) to to enter the engine if your PCV line is hooked up. Any un-metered air entering the engine whether a vacuum leak or improper plumbing will make the PCM think it's running lean and compensate by adding fuel so it's important. Take that filter out and replace with a plastic elbow for a 1/2" line and run a 1/2" rubber line to the crankcase ventilation supply fitting(the top fitting (1/2") on the passenger side of the throttle body). This supply line has already been metered by the MAF sensor so the computer is happy.
2) The inlet to your MAF sensor needs to have a filter on it because even tiny specks of anything will cause it to read wrong.
Remove and clean the MAF sensor with CRC cleaner made for that purpose before you put a filter on it. If possible try to put about 6" of straight hose on the MAF sensor, then the filter. This makes a smooth non-turbulent air stream coming into the MAF sensor which makes them read the flow better.
3) After you fix these items, look over the entire intake for any additional vacuum fittings that might be un-capped. Then check and tighten up all the intake bolts if any are loose.
See if it runs better then let me know. If it runs better then I can direct you to sources for computer tuning if it even requires any.