OK. I just got back from my shop and have it all figured out Basically, what is happening is that the car pan has the dipstick tube coming up between the front and center exhaust ports, while the truck pan has it coming up between the middle and back exhaust ports. That means that the exhaust manifold is closer to the block in the back for a car and closer to the block in the front for a truck. In the following pictures, the manifold on the red engine is a truck manifold, while the individual manifold is a car manifold. In both instances, the left hand of the manifold goes towards the front of the car. I think the differences are self-explanatory.
"V12Bill", I don't see how you could have a car drivers manifold on your truck, because the outlet goes right where the motor mount is on a truck. The crossover pipe goes in front of the engine on a car and under the engine on a truck. The picture of the car with the Fenton headers is just there to show where the dipstick tube is on a car. Here's the pictures :