AMERICA'S FIRST

So what about the light trucks? The engine was a better fit there, certainly in the half-ton GVW ranges. Because it was a special order, the D301 doesn’t appear in any of the main product literature. Dealers were notified of the option and based on the surviving trucks and Line Setting Tickets (Ih-speak for “build sheet”), the confirmed model years range from 1963 to 1968. A likely test mule has been found that was built in 1962 and a batch of D301-powered 1963 Travelalls sold in Scandinavia were among the first to be sold. The known survivors include half to three-quarter ton cab and chassis, long- and short-wheelbase pickups (Bonus Load and Regular Bed) and one Travelette (IH’S crewcab pickup). There are rumors of a couple of surviving D301 Travelalls but they had not been tracked down by press time. Given International trucks’ favorite trick of morphing into rust, attrition is high.

How many IH C-line diesels were built? That is currently unknown, but a wild guess would be in the hundreds for the entire production run. The only hard numbers come from Charlie Horton, who has some paperwork that lists 42 D301-powered trucks being built in ’68 and ’69, 23 being Loadstars and 19 being Light Line. Some 53 D301 Loadstars are listed in his papers for 1970. The engine numbers ran sequentially for all applications and the latest known engine is number 8070 in a ’68 truck, so 8070 engines from start of production in known. There are rumors that the D301 could be special ordered in the ’69-and-later D-line trucks too, but this has yet to be confirmed. Another unconfirmed story says a well-known lawn care company ordered D301-powered IH trucks back in the day. If you have any clues to share, please write.

The D301 wasn’t a superstar in the diesel world but it wasn’t a terrible light duty diesel. It did have some legs, seeing use as a marine engine through the ’60s, as well as being offered in IH’S line of stationary powerplants. It appeared in IH 403, 453, 503 combines of the ’60s and the 1976 715 combine at the last. It was an imperfect design with several weak links that popped up in hard use and was woefully underpowered for 16,000 to 18,000-pound GVW medium-duties. Whatever its faults, the D301 shines as the first diesel option for an American light truck.

 The engine fits well under the hood. No wonder, since the architecture was based on the standard Bd-series gas sixes. This one is not 100-percent original in that the fuel filter on the firewall has been changed from the original dual-canister...

You may only see one D301powered IH light truck in your lifetime but if you had come to the 2017 Red Power Roundup in Des Moines, Iowa, you’d have seen these two. On the left is Pat Putnam’s ’68 4x2 1100C and on the right is his ’65 D1200 4x4. The ’65...

 The strangest feature of the D301 was the hydraulic throttle control. Instead of having a direct linkage, a hydraulic setup was used and it worked much like a hydraulic clutch. Below the pedal was the “master cylinder” (shown) and on the injection...