edelbrock 1406 carb

that's a good size. I had a 600 holley on my 289 and it ran fine, idled fine, and still had decent torque. You also have a little room to improve the rest of the motor, and not run out of carb.
 
cfm is rpm my friend. Theres an equation on all of it, but on a 302 600 cfm is approx 6000 rpm. Its fairly close for a 302, so keep that in mind. Like others said its plenty for most street drivers.
 
The Edelbrock style carbs are cool, and my favorite part about them is that they are really easy to tune. They work pretty good out of the box, but the time you spend tuning your carb for your specific engine combo is well worth the results.