Not really. Drive it to Florida and sell it here. Then buy a used 4x4. You could enjoy a vacation in the sun and get the most possible for a 4x2 and get the 4x4 you desire.
Converting is totally cost prohibitive unless you are a major DIY guy and buy a totalled 4x4 that was rear-ended.
Like cj4flyr said. You gotta have a 4wd 4runner that doesnt work anymore and get the parts from it. The gear ratio. Its more work that benefit. might as well sell yours and get a year or 2 older 4wd.