Sorry for any confusement. I don't mean to swap the engine, but to replace my regal with a impala with 3.9L engine. I want to know some opinions on this 3.9L engine as I don't have any experience with it.
On the other hand, I agree with you that 150K miles is nothing for my car. Problem is that many little things tend to go wrong with such high mileage, which is somehow annoying. I posted last weekend, seeking for suggestion to fix the leaking elbow on the LIM.