Hate to break your balls Sean, but an aluminum block and a lack of a supercharger wouldn't save you 500lbs. Even an iron
BB (around 675) is only about 200lbs over an aluminum SB (450, closer to 500 loaded up and wet). And blowers are not that heavy. I'm sure they could get it down there though.
BTW, doesn't Ford currently make a Cobra???
I'd like to see Chevrolet come out with a new Cheetah. I imagine it looking sort of like the Shelby GR1. Available with either the base 400hp LS engine or the siamesed 500hp LS engine. And of course they would have to make a few with the blown LS9 engine for guys like Leno.