Looking at my Mounting Kit Instructions that came with the brackets themselves (but my mounts are still waiting to be installed in their final location) I see:

Speaker Screw Size = 32 x 1/2" Screws

Stud Attachment = Pilot Holes 3/32" Diameter Holes

Drywall Attachment = 7/16" Diameter Holes

I hope this is the information you were seeking. I also hope we see a review of your new LCRs once they are 'broken-in".
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Marantz AV7702mkII, Outlaw 7220, ,7ea-Outlaw LCR (2ea.- L/2ea.- R/C/SR/SL),Outlaw 7125 for 4ea-Outlaw LCRv2 (Atmos ceiling),Outlaw Ultra-X12 & LFM-1EX Subwoofers,BR/DVD Oppo BDP-103,BDP-83SE, Samsung 65" OLCD, Sofabato remote - Whole house audio via two (2ea) 7125s.