The Irishman: Italian or Sicilian? (Patreon)

I'm working on a video for my noble guardian tier where I'll analyze this scene from the film The Irish man where Robert De Niro and Joe Pesci speak Italian. Is it correct? Is it well done? Is it actual Italian or do they speak Sicilian? If you wanna know the answers to all of these questions, stay tuned! As I'll post the video soon here on Patreon! Just look for a red thumbnail. 

Metatron