If you have a .308 Saiga. Get your conversion stuff from Dinzag Arms. He has FCG and trigger guard assemblies already worked to drop right into a Saiga .308.
Apparently 308's have minor fitment issues and Dinzag addresses those before he sends stuff out. I was going to order from CSS myself, they told me the FCG will drop right into a .308 but I was still skeptical after researching.
After talking to Dinzag, He cleared everything up for me and I just ordered his stuff.