I accidentally ordered a carbine length upper. I meant to order a mid length upper. I did get a 16" barrel which is what I wanted. It appears the carbine length does have a milled spot for the front sight and gas block further down. Can I just move the gas block and sight and get a longer gas tube and be gtg? I planned on tossing the handgaurd anyway and doing a free float. I ordered this from PSA and I don't expect to see it for a month at least. Steve Wanna kill these ads? We can help!