They can’t find them??? Where’d they go? They should’ve never been removed from the radiator to begin with. There’s no need to remove them to do anything related to the engine.
WTF!? Completely unwarranted at this stage! Sounds like they’re not inspecting anything or looking for potential failure causes, despite what they’ve told you, and they have instead already decided *for you* that they’re going to drop another engine in. Less time and more money for them to not...
All 2uzs, regardless of model year or whether they have vvti or not, are technically interference engines. Toyota makes this very clear in the FSMs:
However, for whatever reason, timing belt failure on the pre-vvti 2uzs is often not catastrophic. Perhaps @2001LC has a technical explanation...
“Engine failure” is too broad of a term. But incorrect timing can cause a lot of issues on the vvti version of the 2uz that your 06 has. One of those issues is pistons and valves making contact, which could cause destruction.