Edelbrock Streetmaster 318

Exactly,

The smaller sized 'plenum' on the 'Streetmaster 318' is designed for that purpose,
a smaller CFM-rated Carburetor.

The early Carter AFB's {Advertised @ 500 CFMs'} off the 273 Commando have.
* Primary ....... 1 7/16" {1.437"}
* Secondary ... 1 9/16" {1.562"}

A too big Carburetor on the 'Streetmaster 318' defeats the intent {purpose} of the
low-rise single-plane Manifold.

I have used an older Holley 550 CFM {1 9/16" x 1 9/16" Throttle-Bores} with the
'Streetmaster 318', and it works like 'A Charm'.
Hi Cuda, I was asking a question recently on this forum, regarding a good 4 bl intake for a '69 Dart 273. I don't have many options I've found, however, I did run into the StreetMaster 318 intake for sale online. I have a Holley Street Warrior 600 cfm Square Bore carburetor. You seem to know a lot about Mopars, does this sound like a good match for my engine? The engine is stock but I wanted to add a 4 bl since I was having issues with my 2bl carb and didn't want to put money into a 2 bl set up. Glenn