318, 383 or other? Which one

Yeah I am having a hard time gauging what I need for HP and I'm trying to stay away from nitrous. As far as budget I don't really have a set one but probably nothing over $1500 depending on what kind of job I find this summer. I know his 77 Camaro with a 350 weighs 3600lbs and a 454 isn't going to help that number out any. I know the 454 can put out a lot if built right but I don't think with the basic bolt ons it will be an extreme powerhouse. I will also be about 600lbs lighter which is equivlent to HP. Not exactly sure what my car weighs but I'm sure someone on here would have a pretty good idea.

Another thing that doesn't have much to do with this but I was wondering if there were any small block long tube headers that didn't wrap around suspension components.

Thanks for the comment and keep them coming.