If you're smelling gas it could be your mixture is too rich now that your timing is right. The idle mixture screws might be too far out or (i doubt this) your acceleration linkage needs adjusting. That involves bending the rods though so Id do that as last resort.
Too you got to remember that theyre old trucks without all the fancy catalytic converters on them. theyre gonna smell somewhat like gas. dont run them in a closed garage lol.