The 1968 F-100 was part of the the fifth generation of the Ford F-Series, a highly sought after line of pickup trucks and commercial trucks produced by Ford from the 1967 to 1972 model years. The 5th gen was built using the same platform as the fourth generation F-series trucks, but had sharper styling lines, and a larger cab. The 5th gen F-Series came in three trim levels. The "Custom,” the "Custom Cab,” and "Ranger.” Late in production of the 5th generation, the “Ranger XLT” trim level was added as an option.

This particular F-100 differs from most in that it’s got a 6.0 Liter Powerstroke diesel engine shoehorned under the bonnet. This engine is a 2006 that was donated from a Ford Super Duty truck. The 6.0 is a 32-valve pushrod V8 turbo diesel that replaced the highly regarded 7.3L Powerstroke. The engine has a 3.74 in × 4.13 in bore and stroke creating a displacement of 6.0 liters and utilizes a variable-geometry turbocharger and intercooler. It produces 325 hp and a healthy 570 lb ft of torque. It’s a solid and powerful engine, but a quick search of internet forums and blog posts will tell you that it’s not quite as reliable as its 7.3 Liter predecessor. 

Nevertheless, it’s better than the gasoline powered variants that the F-100 came equipped with from the factory. That’s a fact, Jack.