Go with the McGaughy notch. Waay better built then the dim notch in my opinion. The McGaughy notch plates the front on the frame, then folds under the frame for more support, verses the DM, which is just a plate across the outside of the frame.

 

Will a 15x10 in a 6 and 1/2 inch back spacing tuck in the rear? I'm dropped 7 inches and I have drum brakes if that matters

 

It'll be close. My 275/60 tire is about even with the bed side.

 

i cant find correct sizes so i may have to go down in tire