I am planning on building an XM177E2 clone but would need to know what the configuration of these was.
What length barrel
What receiver (slab side, partial fence, full fence)
What stock (aluminum, shiny plastic, matte plastic)
Slick side upper or forward assist
And anything else that made these different
You should check the Retro forum on ARFcom for the specs.
Bbl length- 10.5 or 11.5, most were 11.5
reciever- any of the above could be accurately used. For a 10.5" bbl, the slab side would be appropriate, partial or full fence would be for the 11.5" bbl.
Aluminum stock
The upper could go either way, the Air Force GAU 5 used a slick side upper.
Geez…I might as well have posted this on the akforum…you guys are everywhere 
I rarely visit arfcom now…I’m not banned but I find it uncomfortable there so i stick with this place and the akforum.
11.5" bbl, full fence lower, aluminum stock and forward assist it is then.
Even though most of that site is shit. The retro forum is pretty damn good.
Exactly. I’m surprised they haven’t splintered off and started their own retro forum site. Most of the best firearms forums around now were all created from refugees of that place.