The domed hoods were ONLY
on 70-72 Chevelles.
Just the PLAIN, DOMED hood was part of the STANDARD SS package, PLUS it was also on the Heavy Chevy option. It was a NON-functional hood, just to add to the SS appearance.
The Cowl Induction hood was an option, as mentioned, RPO ZL2. And was ONLY
available on a big block car.
In 1970, ALLLLLLLLLLLLLLLLLLLL SS cars came with a big block only (396 or 454), PERIOD.
In 71-2, an SS was available with a small block (350)------------------------COWL INDUCTION HOODS WERE NOT
AVAILABLE ON A SB CAR!
ALLLLLLLLLLLLLLLLLLL Cowl Induction hoods also came with hood pins. The CI hood is MUCH MORE than just a domed hood with a flapper valve. The complete pkg requires many additional parts such as a special air cleaner with a rubber seal to mate to the hood duct, a wiring harness, relay, switch on the gas pedal, etc.
The Cowl Induction hood was more or less an additional performance feature and SUPPOSEDLY, under wide open, full throttle conditons, it MAY have added 10hp (there is no factual documentation to support this).
Sooooooooooo, bottom line, a Cowl Induction hood was basically eye candy. For me, personally, I LOVE the CI hood and have added the complete system to my 70 Malibu conv.
This is our 70 Malibu conv with the CI hood added, and it is 100% fully functional.