There have been two different members of the conference that captured the 3A boys' basketball title in four successive years.

[1] The conference's demise was set in motion by the Illinois High School Association member schools initially voting in December 2018 to establish a district football format (but repealing it one year later), meaning Mount Carmel would not be able to schedule all of the other conference members in that sport.

This set off a chain reaction, as Jasper and Vincennes Lincoln were accepted to return to the SIAC for 2020, and a week later, the PAC voted to accept the remaining four schools, including two former members, Boonville and Mount Vernon, effectively ending the conference.

Sources:[3][4][5] Note: Big Eight Conference championships were determined by a single round-robin among the active members.

The Big Eight Conference did not break ties in the standings for championship purposes, instead co-championships were awarded.