Cam swap without pulling motor

You should easily be able to swap the cam with the radiator out of the way. The only other thing that might be in the way is the latch support....if trucks even have one. As far away as it would be in a truck (if it has one) the cam may turn enough to go by it. If it's in the way, there's only a few bolts holding it in. The coolant is far enough down since you have the timing cover off. Those holes down on the bottom front will drain it almost as far as the plugs in the side of the block.