I was told this fits more than just 67’s. here’s the link http://67-72chevytrucks.com/vboard/showthread.php?t=254312
s/t

This set up was available in the early 60's (63 is the earliest year that I have factory literature on) and continued through about mid year 68. The 67-68 set up is basically the same but the power cylinder support bracket is different on 67,8 and the pitman arm is also different. I've heard that the 67 style can be made to fit on 63-66, but I've never tried. The average price on these set ups is usually $150-$250, but I've seen them go as high as $400. I would think the 63-66 would be a little more valuable.
Joshua