I think he's on his 2nd block, the first one was buggered by detonation. As has been said, a rough tune is going to blow up any motor. This guy has also never used the stock rods, they built a shortened set from the start to comp the motor down. So if it was a failed rod that smashed the block, it was a failed custom rod.
Don't sell the stock motor a short, they are as tough as nails. They did have head gasket issues, but as the article mentions, o-ringing the block will soon solve that.
On the block being toward the end of it's modifying potential, I wouldn't let the numbers fool you. AMG also take a 215kw 4.3L alloy V8, bore/stroke it to 5.4L and strap a supercharger to it. Total power is then 370kw and 700Nm of torque. That's a hell of an increase.
Having said all that, I
completely understand you not wanting to pioneer that sort of build. The electronics especially would be a nightmare.
I supposed I am biased, having worked for benz and having owned quite a few, it hurts me to see a relatively rare car being bastardised with toyota parts, especially one with 75,000km.

That's why I've tried to suggest ideas that might allow you to keep the stock motor....
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