What carburetor can be used on the 350/300 hp Camaro that will still allow the original induction air cleaner to be used?

 

That depends on what intake manifold you have and what hood is on the car.

 

My Camaro is 100% numbers matching, therefore it has the original small block cast intake and the factory cowl hood standard on all Z11's Pace Car Replica cars. I'm retaining the original quadrajet but want to upgrade to a better performing carb but wand to use the factory air cleaner assembly.

 

I'd just stick with the q-jet if I were you, a different carb by itself will make little if any difference and probably just provide poor gas mileage.
If you want better performance you'll need a package of parts that compliment each other. If you want a performance carb like a Holley double pumper for it to really do it's thing you need a better intake manifold and exhaust system (read headers and aluminum high rise intake) at the very least and preferably a cam upgrade to round out the package. A carb by itself will be a waste of money IMHO.

 

A taller air filter element would probably help. I run a 4" tall element and it fits under the factory ZL2 hood with a big .block! Stock element is only good for about 600 cfm. The Qjet is 700 cfm on your 350. Y2K is right about changing the carb. How many miles on the engine?
BTW, anybody remember the 1963 Z11s??????????

 

I've read some, those were a bit before my time. My first thought was the famed mystery motor 427 but that's not exactly right, the '63 Z11 was a stroked 409 taken out to 427" for drag racing and the mystery motor built for NASCAR from the same time period was a different animal also with 427" but not the same as the later Mark IV 427 that went into production.
It looked a lot like a Mark IV but shared no parts with the later big block production engines. I found this great read with a google search, very detailed info here. https://macsmotorcitygarage.com/insi...ystery-engine/