Are there any carbine options for an LM replacement upper, or is a standard A1 more likely? Any Air Force carbines?

A friend gave it to me about 10 years ago, I forgot & I "found" it in my safe. I have my 20" uppers, but have accepted RBRD as a chronic condition and this upper looks lonely.

Thank you all.

There may have been some carbines that were re-arsenaled with the LM M16A1 replacement upper. I know that the M16A1 was the biggest recipient of these uppers. I doubt any Air Force carbines were re-arsenaled with any since the vast majority of these carbines were slicksides, but that does not mean that it was not a possibility. I just think it was unlikely.

Not sure if any arsenal carbine rebuilds on the LM contract replacement A1 uppers.  I did score one off gunbroker NOS still in the plastic wrap back in 07. I used it to build my XM177E2. It is more of a charcoal gray anodize, not as black as the current A2 offerings.

You have a fine upper! build it up!