273, could it be a commando and CAM question?
Maybe in Sweden, but here in the USA, a truck can be equipped with a /6 to a 440. The 360 was built and designed not as a performance mill, but as a people mover mill that powered all sorts of common vehicles of the day.
It's first performance appearance was in the '74 model year, in the Challenger, Cuda and Duster.
If you guys want to stick to the 273, great, otherwise, screw the "Truck" monkier and just use the 360.