Well, its kind of normal to have the engine compartment smell like gas alittle. Check your fuel lines. If they are the original Im sure they've cracked or torn. If your passenger cabin smells like gas, its more than likely coming from the trunk. Check your gas tank to see if it has small holes from rust or from old age. Next check the rubber hose that connects the tank with the outside quarter panel fuel inlet. If its an original it probably has a few cracks and holes. Lastly check your truck gasket. A worn gasket will allow gas fumes to enter the cabin. I had the same problem and replaced the rubber inlet hose in the trunk and the trunk gasket and all is well. Good luck!
David