I like the power goal and the engine to do it.
Are you going to sandblast or dip the body at some point? To me, that looks like it would need quite a bit of rust repair. Considering your power goal, I wouldn't leave the body stock. Some careful reinforcements could really help safety and handling, two things that you want lots of when you're messing around with 1000hp.
I recently finished doing a 70's Porsche 911 body and it looked slightly more solid than yours. Then it went on a rotisserie and got blasted with copper slag and glass. I had about 110 hours of sheet metal work on that one after blasting. It needed about 20 patches and a door.