If you've got a stock 3V-ZE engine, you're in luck. The valves shouldn't be damaged. It's a free-running engine.
If you've got a 5VZ-FE, you are likely to need some expensive repairs, like a couple of bent valves and hopefully, no head or piston damage. They can be totalled.
http://www.gates.com/downloads/downl...older=brochure