The main drawback to the 327 "double hump" heads was the lack of any bolt holes for mounting accessories on the ends of the heads. Later model 64CC heads have the accessory mounting holes if you're not building a concours restoration that requires a specific casting number. 64 CC heads on a 350 engine bumps the compression high enough that a really radical cam grind is required to keep the actual compression ratio (not the theoretical) down low enough to run on currently available pump premium gasoline. Otherwise there's a major risk of destructive detonation.

76 CC low compression 350 heads can be angle milled .100" and the combustion chamber volume goes down to 60CC. We used to build "cheater" engines with those heads for the "stock" division at the local round track with 2.02" intakes, 1.6" exhausts, and 60CC heads - - - - -more compression and bigger valves than a camel hump engine. The tech inspectors didn't look past the casting numbers.

"Camel hump" heads are only good for bragging to folks who don't know any better, like a lot of other stuff that's done to old muscle cars.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!