brake system setup

[SS Shaun]

ok so i looked at some of my friends chevelles and i found this


i went to 5 different chevelles from these chevelles 71 ss 72 ss 69 wagon 67 ss and a 70 malibu. none of them had this valve. i asked all of them why they dont have that valve in place. they told me they removed it because it was something they will not need anymore remove it and put the line in place and bleed your brakes and go. so is this valve really need? they all told me you dont need it remove it. and the picture is from my friends with a 69 wagon. he also told me that he is using all of the original hardware as in the distribution valve on the frame. any truth to this?