38" rear spare tire

[2010_5thgen]

im getting all my ducks in a row with this lift. since the rancho kit wont allow me to reuse the stock 17" wheels, i have no more use for the rear spare tire. and being that im going to a 38" tire, i dont think i would want to drive around too much with that much of a difference in size. so my question is, will a 38" tire fit on the factory rear mount? and my next question is should i go with a wheel and tire combo that is the same as what im doing? i have 20" Mazzi Hulk wheels, powdercoated Satin Black with 38" toyo's.... or go with something more for emergency use than appearance? something like a 17 or 18" black steel wheel with the 38" tire? comments, questions, and any input is welcome.