he only thing coded into the full VIN would be the engine option. Trans, axle ratios, etc are not coded in the VIN.
The partial VIN on the frame gives the nameplate (Chevy vs GMC), model year, final assembly location and the sequential portion.
The VIN is stamped on the top of the frame rail (not the side) in one or two locations. No crossmembers get stamped. There's the VIN on the cab and some assembly plants (Oshawa in particular) would stamp a partial VIN under the heater box for some years, not all. Engine and trans get a partial VIN, not the axle(s). The SPID label is the equivalent of the old body tag.