Louis Ruel and François Goupil pleaded guilty on Friday.
Ruel and Goupil had also been facing charges of first-degree murder; those charges will be dropped Monday, according to the Crown.
Earlier this month, Jacques Dumais also pleaded guilty to conspiracy to commit murder.
The biker mega-trial is set to begin Monday, Aug. 3 at the Gouin courthouse in Montreal. The trial is expected to last between 18 and 24 months.
Seven associates or members of the Hells Angels are still facing murder and conspiracy charges.
They were arrested in 2009 as part of the SharQc sting operation, which netted 156 arrests. Charges included murder, conspiracy to commit murder, drug trafficking and gangsterism.
More than 100 of those have pleaded guilty, while 31 others were released in 2011 after a judge ruled there were unreasonable delays in their cases.
Three people have died since being charged, while eight others are still at large.
The final two accused, Robert Bonomo et John Coates, have a trial date set for January 2017.