The Factory Assembly Manual might not help much. It has diagrams for 54/55-1st (Section 10 - sheets 2.00-2.05).
For all 3100s, the wheel carrier was basically the same - the bolt goes up through a cross-brace between the frame side-rails (and, I have no hole in "rear sill" in the 3106 Suburban).
The 3600 is different (Denny's model of interest).
Two different styles of wheel carriers are shown (for 54/55, at least) for 3800 styles of trucks. One style has a bolt that goes into cross-brace between the frame (the 3805 Panel & Canopy). Other 3800 models bolt to a frame side-rail.
