What would I gain from a 4bbl on a 273?

Doing a quick glance at the motor yesterday I found the intake casting #2536559 and the #R 273 225 stamped in the block in front of the LH head. I'm not real clear on the block number. I'll have to pull a valve cover to chech head numbers today.

Dam*ed milkcows don't give me any free evenings.