Just got this Colt upper, anything special about it? Im gonna post it in EE eventually.
What should I ask?

We really don't have an appraisal thread in this forum, but I'll take a stab at it.  Upper is a commercial Colt A2 upper due to large-hole pivot pin.  You can still use these large-hole uppers on lowers with mil-spec pivot pins, but you'll need an adapter bushing.  Finish is light to medium gray anodizing, which is typical for Colt uppers & lowers from mid 80's to mid 90's.  Without the forward assist and ejection port cover, I'd say it's worth $100 bucks plus or minus $10 either way.  I'm not sure from the picture, but the take-down hole looks like it's been enlarged to fit a specific lower.  If that's the case, I'd knock off a few more bucks off the value

Nothing really special about it. I have the same upper on my 1986 Colt AR-15 A2...




And my 1993 Colt Sporter Match HBAR MH6601