Not to stir the pot, but just because you work on all kinds of engines doesn't mean you know what your talking about.
My old mechanic blatantly got in face and told me I was full of shit, when I told him not to swap in another spi (due to the valve problem) when I was looking for a new engine after my spi went out.
He said he had been working on cars for 35 years an has never heard of such a stupid thing as a valve seat problem on the SOHC focus. I shouldn't believe the stuff I read on the internet. He refused to swap in anything than what the car came with from the factory. I went and pick the car back up the next day.
Do one thing every day that scares you. -Eleanor Roosevelt