Had 329K on orig 3.0, Toyota replaced it when the headgaskets failed. The mechanics at my local dealership (who did the work)said it was the highest mileage they had ever seen with the orig headgaskets.
Needless to say, im a lifelong Toyota driver.

(BTW, this is my 5th Toy 4x4 (1)87'pu,(1)82'pu,(2)84'pu,(1)86'4run)