FF is 100% correct.
I'll cover a few other bits from page #2 of the rulebook "Rolling Dice" --
1. We do not use a die type bigger than d12 or smaller than d6 in Pulp Alley.
2. If a modifier would shift a character's skill die-type over d12 - then you roll d12 for that skill.
3. If a modifier would shift a character's skill die-type below d6 - then they can
not roll any dice for that skill. Effectively, this means they automatically fail if they end up in a situation that can only be solved by this one skill.
Please let us know if other questions come up. THANKS for playing Pulp Alley!