What's the issue with running the original support rods when you have Vortec heads? I haven't done Vortec heads on a TBI so I haven't experienced this setup. I'll take a wild guess and assume whichever intake you choose to run, since it can no longer be the original TBI intake, doesn't have the attachment points for the original supports?
I'd say the supports are probably necessary to keep stress off the brackets. They're going to have some degree of force pulling on them under the tension of the belt and motion of the accessory drive. I'm no engineer but engineers don't usually get away with adding -anything- to a design that isn't necessary, because it gets bean-counted right out. "Why are we spending this extra 5 cents per vehicle on this support rod?"
Richard