We call the lead truck on the 765 the "Pony Truck." The term "Pilot Truck" is equally correct. The truck at the rear of the locomotive under the cab is called the "Trailing Truck." Both terms describe their location on the locomotive.
"Engine Truck" is a meaningless term. First of all, the "engine" is the cylinders, valves, valve gear, rods and wheels. THAT is what constitutes the "Engine." To refer to a "Locomotive" as an "Engine" is not correct. The "Locomotive" is the machine that carries the "Engine" and the other appliances, such as the boiler, air pumps, etc.
The term "Engine Truck" is also a very vague term. WHERE on the locomotive is this "Engine Truck" located? Your guess is as good as mine. Besides being incorrect, the term gives no hint as to its supposed location on the locomotive. Don't use this term.
