Lexus RX Engine Problems
Lexus RX350 2007: Are they reliable?
It’s unlikely that a manufacturing fault should show up after 11 years. I suspect that you’re just unlucky and its one of those freak thing that can happen. Even the best cars sometimes break down.
Leave lexus alone
I WOULD expect the engine is suitable for conversion, but I haven't been able to find anyone who has converted a Lexus. I wouldn't be the guinea pig.