I don't know, why don't you ask Matty Madonna and Herbie Sperling and Joey Gallo.. The O.P. states black gangs but there are numerous instances of the Mafia affiliating, associating and doing business with other ethnicities historically. You have Casso and Balagula, Paul Castellano ordered Nino Gaggi to instruct Roy DeMeo to murder Chris Rosenberg because of the Cuban Crisis in 1979
Barry Seal, Mickey Mundae, the Cocaine Cowboys and Don Aronow were all non Hispanic Whites and all associated and worked with the Colombian cartels.
On a street gang level it becomes not only about ethnicities but about poverty which cuts across all ethnicities in this country. One needs only to venture into poverty stricken areas in Arkansas, Mississippi, Kentucky, Michigan, Illinois and West Virginia where the quest for affordable housing blends different ethnicities together, White, Black and Hispanics.