67 Barracuda- Brakes and suspension on a 5000 budget- advice needed

I'd ditch those 15" wheels and move to 17" with smaller walls and wider thread widths. Larger torsion bars, add front and rear sway bars, Offset upper a arms at least or QA1 or similar upper A-and get a modern alignment. Dr Diff 13" front and 11.625 rears with a 15/16 master cylinder with handle brakes. Add some good socks like Bilsteins, Fox, Viking, Hotchkis etc. Lots of posts on non-drag racing, street type to high speed track handling.