Depends on how much work you want to do and what your state emissions laws are like.
Scratch fairly new. You could supercharge a 3.8/3.9 Mustang but on that budget you either get the supercharger kit or the Mustang. You don't get both.
Get an '80s G-body sedan. Powertrain doesn't matter because you are going to take it out anyway. Chevrolet 350, decent TH350 trans, 10-bolt posi and that should do it for your budget. Few hundred more in steering, sway bars, springs...etc... and it'll do as well as any Monte Carlo Super Sport in a corner.
Want it out of the box fast? Ummmm.....you might be able to score a Supercharged Grand Prix or Monte Carlo. It's going to have well over 100,000 miles.
Maybe a Chrysler 300M. There's not much you can do to them though. PCM swap, exhaust, throttle body...might get you to 260 at the crank.
That $3500 mark puts you down in the LT1 Camaro or high mileage LS1 group.