Pretty basic question. I'd assume the Genoese and gambino families have the most working relationships due to size. But in the past and present what are the most closely related? Also specific examples would be cool, unknown or less known than the ones we all know.

Today? The Genovese and Lucchese families are the two most closely aligned. Hands down. Especially the Bronx/Westchester factions, especially in construction.

I often wondered does the philly fam and the decavs work together? Specifically scoops licatas crew and any decav joint operations or any known conflict? I dont recall reading about any connection with ohi and decav but def just an educate guess..any insight?

Westside and DeCavs would have to live in each others pockets in Jersey.

Like pb already mentioned.. The luccheses and the westside in the construction bussiness...

In the early 1990s George Fresolone of the Philly North Jersey crew was able to get an indictment against the boss of the Decavalcantes at the time, John Riggi when he flipped.

http://www.nytimes.com/1990/08/22/nyregion/41-charged-in-mob-case-based-on-informer.html

More info on the background information of how Philly LCN is still to this day able to have a crew in North Jersey:

http://citypaper.net/articles/041901/news.mob.shtml