You want webers with minimal filters and a lumpy cam. That's how you get the rorty weber note happening. A holley or other regular downdraft is muffled by it's restricted air paths. My brother old 1600 with L20 (with 2.4 crank/pistons) sounded like the business. He was running twin 48 webers.
However, a CA18DE with a filter sock on the end of the AFM sounds very similar. You also need to get the exhaust note right too. Always run a resonator, otherwise it will just be loud, but not nice.