Don, you are correct. The S10 frame mounts the engine forward and near the front axle centerline. The Model A mounts the engine further to the rear relative to the axle centerline.

Thus, the builder needed to move the engine back out of the radiator.....so he (she) shortened the frame to move the engine back....duh, the front wheels moved back at the same time.

This is a great picture that Bob posted....a classic (the picture, not the car).

mike in tucson