I would like to know the gas port sizes for:
308 14.5" Mid length gas
308 16" Mid Length Gas

And 308 16" rifle length gas

Also if someone knows the merits of 16" mid length vs 16" rifle length, or could suggest which of these 3 settups would be optimal and why that would be good to know.

From the outside looking in, 14.5" and 16" mid length gas look like good settups to me, with the edge going possibly to 14.5" mid over 16" mid, while the 16" rifle gas appears to be a possible reliability compromise that could yield a finicky operating firearm.

I had my 20" rifle length Krieger barrel cut down to 16". If I remember correctly, I believe the the gas port measured .93, and it wasn't touched after it was cut down.
I've had no problems with it cycling after about 50 rounds I used as a break in. Besides the break in, I've put around 200 rounds of 175gr FGMM, and it has yet to to fail to eject or fail to hold the bolt.

Im surprised the 20" port functioned unaltered.  What wad the buffer weight in your rifle?

The KAC guns are rifle length gas 16" aren't they?  Perhaps only mid-length.  Definitely longer gas system than your average DPMS though.

They are rifle gas 16" barreled.  

My comment was that I was surprised it ran unaltered with a 20" gas port.  

Anyone know port specs for mid length 16 and 14.5" gas?