Just got my ORD shackle flip brackets in on my 70K5 with '72 K20 axles. Has anyone who did this drilled the bracket for the rear bumper brace bolt that is in the middle of the shackle bracket? Were you able to get a bolt in there or was the the gusset of the shackle flip in the way? It looks like it might clear the gusset but I don't want to drill it till I know for sure. If not then it's time to build my custom rear bumper now.