its plated over the frame to reinforce and make it stronger at the attachment point. It is welded all the way around the plate and then plug welded in the middle. When you cut all the stock metal off the frame and then grind it down it weakens the frame in that area and the frame will sometimes rip. I would weld the hole that you were talking about. When you put a stress that close to a hole it cant tear the frame.
after rewelding all the factory seams on the shock tower for strength and running gussets down where else are you supposed to get support from without using the shock tower?
im not trying to critize your work, when my bracket broke it bent my shock tower back past the steering linkage and it was a pain in the but to get it back down to the original spot. thats the reason i put the two gustes running upwards. but im no pro at it as you can see!! the first pic on page one i redid the welds when a good person on here brought it to my attention but the welds didnt penitrate the bracket that well. i think it was the wire i used. when i re did them the second time i used .035 my teacher said it will be strong enough if i put down multible welds to support it, because of my machine being a 110 amp mig.
im taking the truck to a local guy who specializes in bagging and bodydroping. he is going over all my messups and bagging the back with me i have just linked up with him and he does all the baddest trucks around here. i seen alot of his work and it is incredible. if i can get some pics of his stuff ill post them up.