I have a little less then 12k on this chrome and it has taken some abuse!!
I have pulled a 5400 lbs boat over a the "three sisters" and sustained 50 psi for a little over 4 miles. The EGT's were not and issue, but collant temp was.
I also have the heater core metal pipe that goes right above the manifold and t stat housing chrome. They are both as shiney (is that a word??) as they were the day I installed them... I would think the heater pipe that is above the manifold discolor first, but it is fine.
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