1963 GMC 4000

Okay Jolly, here is the pictures of the engine:

The Engine number

Best I could make out:
401M 03I--6

I couldn't read what was after the "I" in the code (probably a 1 since the 1 in the other engines I have are "I"s.  For accuracy though I will just call it an "I").  I could read the zero, three, and I, then some grease and couldn't make out the numbers, a small hole (like it was punched or tapped with a drill) then the number 6

The data plate.  I thought I took a picture of the VIN, but I don't see it on the camera.  Hm.
Anyway, the VIN is VH4016 G1750F
This plate says 24000 GVW
305C engine with certified net HP 142 @ 3800 RPM
Opt. 351 with certified net HP 155 @ 3400 RPM

The visor indicates shift pattern

Data Plate from inside glovebox door:
Model : VH40I6
Serial : G1750F
Front Axle: F070
Rear Axle: EI6802
Axle Ratio: 6.14 - 8.54
Number of Spring Leaves:
Front: 7  Rear: II  Aux: 4
Engine: 35I
Trans. Make: NP540
Type: GL
Speed: 5DD
Service Brakes: HYD
Wheels: CAST

That is all I *know* about this truck.

Can't see it too clearly, but there is a lever to shift the rear axle in the shifter knob.  There is also a lever and round "box" fastened to the steering column.  Has 5/8" approx hoses to and from it, which go to a regulator under the hood.  These appear to then run to the rear of the truck.  Appears to be a brake control for a trailer which used air brakes.

*NOTE* hood was removed and cleaned.  We put it back on the truck.  That is the color the truck would be if all cleaned up.

The Bed is 20' - 6" long from tail to headboard.  The truck is, overall, about 29' - 6" bumper to bumper.

The rear duals are one rim.  Actually, they look like 2 rims connected by a filler peice.  But it appears to be all welded into one component.  The spare is a single wheel.

In addition to the in cab tank, there are 2 of these tanks.  Appear to be 30 gallon barrels, on thier sides, well cradled and with filler necks, caps and basically set up correctly to be used as fuel tanks.  Maybe an older "aftermarket" style?