Toyota Repair: 2000 Sienna Sludge, correct recommendation, warranty period

Question
Hi Ted, My 83,000 mile 2000 Sienna has an advanced case of engine sludge. Consumes 2.5qts in 300miles, etc.  I purchased at 23,000 and have had my oil changes dones regularly at the dealer w. Mobil 1.  Dealer has agreed to engine rebuild including short block. 1. What should I be asking them to replace (?on my dime) that they might not otherwise. 2. Dealer sez rebuild engine will have 12/12,000 warranty - which seems short to me. your thoughts? 3. I'm leary about whether I should hang on to this vehicle or look for the next one before the 12/12 runs out.  thanks

Answer
The dealer is giving you the correct recommendation and being professional they should know what to replace, the warranty period is standard in the industry.
It is completely your decision whether to go ahead with the repair or trade it in on something else, I can't make that decision for you.