Guys, I hate to expose my ingornance (again) so blatantly on here but I see no way around it. I apologize for not knowing all the correct terminology.
I have spoken with Smith and Wesson this morning and here is what they have to say. My rifle is a "same or single plane" rifle. Both rails being level with each other and therefore I need a "hand guard" or "same plane" front sight. They didn't offer any suggestions on who supplied this type of sight.
I see from some of your comments above that you have already determined my error on using the work "gas block". Again, sorry for the confusion. I'm being told that a "LMT front sight" will do the job. Here's a picture of one that will allegedly work (second one from the top)
http://www.bravocompanyusa.com/AR15-...ights-s/57.htm
I prefer the look of the triangle type or style. Does anyone know any other brands of this design that will work?