slit smell of fuel

depending where you live but if its colder where you live its probably just the temperature not properly letting the fuel atomize aka you can smell fuel also could have a small leak on the carb that evaporates b4 its able to form a drip thats of course if it has a carb which it may not since its a vette other causes could be a sticky injector allowing excess fuel to flow into the cylinder and not get burned properly which can cause a fuel smell. Or you may have a small leak on the fuel rail gas evaporates pretty quick sometimes especially when its under pressure get a fuel pressure gauge set or borrow someones it should be a pretty fool proof way to see if its leaking or not. First Check the fuel pressure at the fuel rail using the proper Gauge set adapters. If pressure appears good preform a fuel volume test take an empty 20 oz bottle with the vehicle running using the bypass hose on the fuel pressure gauge set stick the hose in the bottle hold in the button or valve and within 10 seconds the bottle should be at least half full if the engine dies or if the bottle is not at least half full there is a leak someplace or the fuel pump is weak but the pressure gauge should tell you this before you preform this test.

unburned fuel in carb.or bad egr or the rubber hose that hooks to it is bad.