it depends on the cam you are going to use, not just the displacement and heads. but for a street engine i would use the edelbrock performer series carb in 600cfm.
I would tell ya what Arron Johnson suggested to me about vacum vrs. mechanical secondaries but i dont want to start another bash session ................... but I WILL TELL YA THIS ..................... other than an all out race car ................. vacum secondaries would be the ***** choice !!!!!!!!!!!!! ...................................... LOL
Vacuum secondaries are the only way to go for a street engine. I personally would run a 650 or 670 depending on what brand you want to go with. Holley or Demon imo.
for the street a 650 holley or edelbrock would work great. like advised earlier, change the spring in the vacuum secondary on the holley to a lighter one since you are running a stick. a mechanical secondary 650 may give good power but has a chance of suffering fuel mileage