I don't know that there is any conclusive evidence - without before and after dyno runs to determine actual power and torque levels, everything is pretty much conjecture and speculation. While I stand by my theory of low torque loss, I have a lot of respect for OldColt's knowledge and experience with Mitsubishi engines. He has far more experience with all types of Mitsu engines than I have - my automotive knowledge and engine building experience ranges across the board from small block Chevys to Nissans, Datsuns, Toyotas, and Mazdas, to Opels, air cooled VW's and Hondas, but my 3.5 DOHC is my first Mitsubishi engine.

I guess your best bet is to take all the suggestions and knowledge that you read here and use it to make your own decision. Better yet, get your Montero dyno tested before you do anything and then again after you do whatever repair you end up doing - you can be the first to provide the community with actual factual data.