I was looking at the lower control arms , thought I was seeing 1 single runner/arm . But then looked closer and I seen the other side of the runner/arm . Did you do anything inside the frame rails like putting some box tubing inside of them for stiffness ?
no you dont want to cut into the front frame rails. they are two piece ( a bent channel and a pop riveted top) there is no boxing needed. You run your sub frame from the back clip to the front