70 Dart/Paxton Blower

Well let me go look. Yea you're right! Never noticed it was gone until you mentioned the top radiator support being gone. Seems to be holding up fine. He must have done that for clearance issues.
I would fabricate a bracket that goes from one side of the core support to the other. It would probably be bolt in, so, I would use at least 2 bolts per side. maybe reinforce, or get an aftermarket lower core support brace. would require welding though.