Ak's need side rails
I'd get one of these and screw it on there
:
http://www.collectorssourcedfw.com/mpk-2.html
Currently out of stock, but the best screw on side plate out there, IMHO. These are the grandkids of the ones Tantal sold back in the day ('90s). Just remember parallel to the top of the receiver
They aren't as versatile as some of the rivet on rails but do the job nicely. If you like your Poly and would like to see what you're shooting at, I wouldn't hesitate to put one on. If you're looking at the investment aspect then maybe you want to sell the poly and pick up something else.
The install is stupid easy. I've done at least 5 or 6 and only got the first one on slightly crooked. Didn't effect zero ability with PSO's or red dots and only I can really tell.