whos running big cubes with carb on the street?

I dont know about the mileage since that has never really been tested on a large motor like that, especially being a stroker. I do know that pushing 427 cubes out of a windsor is a tall order and so I doubt you'll get that kind of mileage out of it. The other thing to consider is the low mileage you will be putting on it. So even if the motor is only good for say 30-40k, that will last you like 10 years or so. I think a 408 can easily live on the street since its really not asking too much of the 351 windsor block, but it all really comes down to the cam, heads and abuse you put on it. As for carburetion I would go with something in the 750 range and go with either a Holley or Demon. If its a summer cruiser and weekend pleasure car with a few trips to the strip then go for the vac. sec. carb since they perform better on the street, get better mileage and still pack a good punch at the strip.