So I'm deciding on installing one of those drop in gas piston conversions such as the OPS-416, the only problem is I cant seem to find any info on which Free float quad rails it will fit under. Also was looking at LWRC they have a nice setup going but do they have a conversion kit? I have a A.R.M.S. #41-B Silhouette, so getting a new gas block is not gunna happen. Any thoughts?