ZL-1 & L-88 head design clarification

[nuch_ss396]

Guys,

I had often heard that the '074 ZL-1 heads, with their
round exhaust ports, we an ineffective design concept.
The amount of power required to take advantage of this
port design was impractical. In my research on building
big block engines, the '077 ( over the counter ) heads
seemed to get the thumbs up due largly in part to their
"C" shaped exhaust port designs. Can any of you support
or refute this information? I see the '074 heads on ebay
all the time and often wonder why people will pay big bucks
for them if this it truly the case.

Steve