Whats going to hold it all together once you trim all that off? I bet you will only save three pounds cutting all of that of. There really isn't that much weight to a factory K-frame
I agree, the weight savings is not tremendous but I bet it would be more than 3 pounds. Everything adds up...
In regards to holding it together after trimming; what I was saying before is that I might want to try and cut the bottom part of the flange and only trim the top half to where I could bend/hammer it down to meet where the bottom is cut, then weld the seam there.
