AHC works good. Never had leaks or anything . Timing belt has not been done . This is my second one and first one had done at 115-120k I have driven the truck gently to moderately then yes you can safely extend the timing belt change to 120,000. Toyota uses an extra heavy duty timing belt on interference engines like mine for an extra margin of safety against timing belt failure. Hard charging, pedal to the metal type drivers need to change the timing belt at 90,000. I will send pics in the morning of the under carriage . No surprises, it has your typical surface frame rust but nothing to look twice