I have an 83 v6 when i crank it up it blows white smoke and you can smell gas lots of it for a good 30 seconds i just put a new o2 sensor in it and im thinking bout rebuilding the carb just wanted some insight Thanks

 

White smoke is really steam. In many cases it is caused by moisture in the exhaust system getting heated up and blown out as steam. This only lasts until all moisture is converted to steam. In more serious cases, it is caused by coolant getting into the the combustion chamber and getting blown out as steam. In your case it is probably just condensation in the exhaust. The fuel smell is probably caused by the cat not lighting up right away, normal in these old cars, and by the unheated O2 sensors which do not work until the exhaust temp gets high enough to wake them up.