As rc330s said, with absolute minimal rubbing of the tire on the frame at full lock (seriously, it hurts nothing, and if your tread doesn't have big lugs, you might not even know), you can go 235-75/15 on stock rims with only adding 1" spring spacers (and an alignment). Anything smaller than that, no lift necessary, and even at that size, depending on your wheel's backspacing, you might not even need the spacers. But you'd be happy you did. Leaves you several tire choices wider and/or taller than those 205/70s.
Besides, my 2003 Tracker came from the factory with 215-75/15, so your dad's on crack. Not that there's anything wrong with that.