08 F450 B&W companion Hitch install

Can anyone tell me what holes they used to attach the pivot arms when installing the b & w companion hitch in a 08 F450 pulling a 09 cyclone 3210.

F-450 & B&W Companion Hitch

I'm not sure but I know when Tim at RV Solutions did the install for me on my 08 F-450 he said he needed to install them at the bottom holes. I"ts pouring cats and dogs right now so I can't go look, but as soon as it lets up I'll take a walk out to my truck and let you know