Ok, thanks! I got the delta ring off by hand, and I decided to order a new gas tube and barrel nut, that way if need be, I can just swap the other upper right back on.

To build the full upper to be able to just swap one out for the other (transferring bolt, bolt carrier assembly, and charging handle), you'll need:

Receiver, barrel nut/delta ring, crush washer, weld spring, handguard, handguard cap, Gas tube, Gas block, gas tube roll pin, gas block, and barrel.

Or alternatively, if you install a free floating handguard (which usually come with their own barrel nut), and which I highly recommend!!!, you would need:

Receiver, free floating handguard set, gas tube, gas tube roll pin, gas block, and barrel.

If you get a stripped A2, A3, or A4 receiver, then you will also need the forward assist assembly and ejection port cover assembly.

No worries though, I'm not trying to scare you off, I just don't want you to be disappointed when you're short some parts when that big box arrives!

Yes I am going the free float route. The barrel, free float handguard, offset screws, and barrel nut came today (with the handguard).

The wrench, roll pin, and gas tube should be here tomorrow or monday! cannot wait! I got the stripped, slick side reciever so didnt have to deal with the other stuff. Thanks!