pssst! The tire is made out of rubber. The wheel is made out of steel or some aluminum alloy (I think) depending on what kind of wheel it is.
You will have to check the back spacing and the bolt pattern. Assuming your '03 is a prerunner or 4x4 model, the bolt pattern should be the same (6 x 5.5"). If you are driving a mini, then you will need to convert it to 6 lug. As far as back spacing goes, you should be fine running 31" tires. Most people run around 3.75" backspacing on their aftermarket wheels. best thing to do is take off a wheel and put the one you want to get on there to test fit.