I don't know anyone that does the subgrame fix in toronto besides replacing the subframe itself.. It looks like you can buy the reinforcement plates from Randy Forbes for 600USD and then have someone weld it for you. Or you can go to Randy he lives at Ohio which is not far from here.
Email him at Erandyforbes@aol.com
and ask about the PDF outlines about the work he does.
PS: You will need a new LSD with dual ears..
Check the fix images here