I am considering offering a kit that will eliminate the 2-3 flare that happens when folks use some kits in their C4s. The Kit will contain a drill guide, a tapping guide, an adjustable restrictor and lock nut. It will come with detailed instructions (with pictures and text) and a list of which tap and drill to buy. (you can get them cheaper than I could sell them to you with shipping. I am thinking the cost would be $15 plus postage - but that depends on how many I make. (the more material I get at once the cheaper it will all be) Is anyone interested in the kit?