behind the carb is a intake vac were do I connect it to does any one have a good diagram or pic Or a good example on were it should be connected to any please...and can this be the reason the car smells like gas after it sits for a little bit

 

If you're talking about the big threaded vacuum port on the back of the carb, it goes to the brake booster.

The type of carburetor would be extremely helpful; '91's didn't come from the factory with carbs at all.

 

it is not on the carb is behind it is on the intake manifold