Nice. Yeah I had a guy give me a long history lesson on the truck on Reddit a while back.
"For those who may not know, this is quite a rare model.
The [IH C-900] was a value-leading base model that was made by taking a half-ton C-1000 and replacing the 7' short bed (IH short beds on '61-68 models were 7', not 6.5' like the Big 3) with a special 6' narrow ("stepside") bed. The only other IH trucks that used a 6' bed were the [Travelette crew cabs], but those were almost exclusively wide straight-sided (or as IH called them, "Bonus-Load") beds, and the C-900 was narrow bed-only except in Canada (because of *course* Canada gets the weird things). In 1965 the pickup line was renamed D-*x*000, then *x*00A in 1966, then *x*00B in 1967. This is where OP's truck comes in.
The engine in the C-900 was the 152 slant-four out of the Scout (a 304 V8 cut in half). The little engine was so weak (for a pickup) that it needed an insane 4.09 rear end just to get moving, which meant that it wasn't very economical. So for 1967, it was replaced by the 266 V8 from the regular pickups, and the 900A became the 908B. The bed and wheelbase were also lengthened slightly, with [a new 6'8" straight-sided bed] and 115" WB (compare to the 7' short bed and 119" WB on a regular 1000B half-ton). This may have been because the super-short wheelbase (107") on the 900 gave it a rather ...disruptive ride on washboard gravel roads.
There are very few examples of 908s with a narrow bed. In fact, until now, I wasn't even 100% sure IH made a 6.5' narrow bed for the 908. The only distinguishing factor between 6', 6'8", and 7' beds is the distance between the back of the cab and fender, and this is easiest to spot on the narrow beds.
The line was renamed *x*00C for 1968, then the whole Light Line of IH trucks was redesigned for 1969, in what would be its last hurrah. The 908 pickup didn't survive the transistion, but the bed lengths were standardized at 6.5' and 8', just like the Big 3."
Not sure how accurate it all is but seems well researched