Is there really any dif between street carbs, and marine ones, besides dif vents and being water tight.

Can marine carbs work on cars and vice versa?

The marine duty carbs I've seen are not necessarily "water tight" but are supposed to be splash resistant, and possibly use more corrosion resistant exposed parts. The venting is all collected and vented out the hold, as you indicated. The rest is fairly common.

yeah i think they are made of brass or some crap on the outside

Would one be able to work on a car?

I looked on holleys site and edelbrocks and they say marine carbs should never be used on the street. but dont explain why.