Anders,
You do not have any problem with that setup whatsoever. That upper open area is just an open air chamber that does not connect to the heat crossover. Maybe it was Pontiac's version of an air-cooled engine? [img]<<GRAEMLIN_URL>>/hmmm.gif[/img] Or it might have been a way to isolate the very hot cast iron above the exhaust riser passage from the oil that would be spraying on it from the rockers. Maybe a way to eliminate cooking the oil and creating a sludge problem? [img]<<GRAEMLIN_URL>>/hmmm.gif[/img]
Here are the 6X heads on my Gramma's 75 Firebird with a 1972 4bbl intake bolted up. As you can see, there is no leakage (since the paint is still intact and no soot is showing). No exhaust leaks either. [img]<<GRAEMLIN_URL>>/grin.gif[/img]
