GM knows this is a very weak spot which is why they sold a reinforcement back in the seventies for it. They also changed the hinge design and made it come out longer to support the hood better.
Check out the dealer to see if they still have the reinforcement for sale.
As far as repairing the hood, those are a beeetch. You will need to really weld it, no propane torch for this one.
Do you have access to a MIG?