Comparing 1935 and 1936-39 Chief frame necks

I get this question alot, and I'm not an expert on anything. So if this helps. the frame directly above is a true 1935 Chief, see how the neck is "hollowed" and theres no shifter bracket. Pretty early for a neck lock too. Now look at the 1937 Chief frame w red tank, the neck gets thickened in 1936 to 1939, no shift bracket in 1936 it shifts off the trans tower in 1936, 1937 introduces among other features, shifting via a linkage. HD big twin frames thicken the neck casting in the 1947 models ,i believe theres 3 maybe 4 variances in frames that year.