[gordon]

The Dodge referencing system is a little obscure Oliver, but in general terms....

WW2 US Dodges are primarily T, V, and W code trucks

T = 1939
V = 1940
W = 1941/47

The 39/47 series all shared the same cab so it's convenient to think of them as one lot.

Looking at just one year;

TC = half ton 4 x 2
TD = 3/4 or one ton (TD-15, TD-20, TD 21)
TE = 1.5 ton
TF = 2 ton
TH = 3 ton regular duty
TK = 3 ton heavy duty
TKD = 3 ton diesel

Pretty much everything was available as chassis cowl, windscreen cowl, chassis cab, or complete truck. Separate bodies were available from a host of manufacturers like the Metropolitan and Montpelier stepdown panels and COE conversions in 1939 (later replaced by Dodge in-house COE 1941-up.

If you have a third letter on the model code it's for extra features, like TKD is a TK Diesel, TKDA is a TK Diesel with 2 speed rear axle
The number at the end is the chassis length, VK 60 was 152" WB VK 61 was 170" WB, and VK 62 and VK 63 were 188" and 205" respectively.

That's the simple bit. Just like other manufacturers you could take a small chassis and uprate the suspension, axles, etc for particular loads or duties. From 1941 up, the W series also had 'M' trucks in there which were COE, so WF was I.5 ton, WFM was 1.5 ton COE. A VH-48, which you mentioned, would be a 1940, 3 ton regular duty, 178" wheelbase standard 4 x 2 truck, with no COE, dual speed rear, or anything fancy. Of course the army could have downrated it to 2 ton for a specific job.