Tires: Replace tires with different tire size, ford econoline, tire world

Question
Have a 1981 Ford Econoline 1/2 ton van. Current tires are P235/75 R15.  Can I replace with P195/75 R14 or other size and if so are there any implications.

Answer
Karen,

These types of vans are peculiar in that they occupy a kind of "corner" in the tire world.

You can only use P235/75R15 XL (Extra Load) tires.  The reason is load carrying capacity and the physical size of the rim (6") and the physical size of the fenderwells.