Ok so tell me why ....
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This one you can kinda see they took 3 pcs of plate alum. and welded them in..
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At least the chambers look decent
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Oh my.....

MSHP to the rescue...

Looks like the engine was running right - the chambers look good.

I haven't the foggiest clue why someone would do that.

Tom

I think I remeber an article years ago where MSHP claimed that the type 4 heads would flex in the area causing leaks on big bores and Hi-Comp engines. They would weld the plates in to bridge this area to add strength.

Ed

Well, normally there's a piece of tin that is that exact shape. So there's probably not a HUGE loss of airflow. I'm definitely not recommending it as an "upgrade", but I suppose it makes sense.