70 340 Distributor

Restoring a # matching 70 Dart 340,Wondering if I have the correct dist,I have some Questions 1 is there suppose to be a tag on it? 2 is there a difference in the 318 and 340 dist performance wise, The housing is aluminum and a # stamped on it 2444259 and after that there is 13 6. any help? Thanks Rick