Best BB bang for your buck?

For that kinda cheap I would go with a 383. They are overlooked, underrated and foggotten. 440s are a tight fit. REAL tight. the low deck motora fit a lot better and open up more possibilities for exhaust. The 400, though more cubes, will require literally .100" milled off the heads to get compression barely in the 9.1 range. Then, you gotta mill the intake a bunch, worry about adjustable rockers cause now the pushrods are too long....blah blah. Find a 383 and build it. You can get decent compression with stock heads and pistons and make plenty enough power to make an a body scoot. I gotta few things for a 383 if you're interested. they are just takin up space here.

Good advice. That's what i would do.
I would get a whole car that runs and has good and even compression and oil pressure. You need to rob all of the drivetrain parts off it, rad etc. Any extras you can sell off to fund the project. I would go with Schumacher mounts and headers. Exhaust manifolds might fit, but might be a major PITA.
If you scan e-bay and craigslist or even go to swap meets, you might find the Shumacher stuff for a lot cheaper than new, same goes with a 4 barrel and carb.
You still need at least A body V8 torsion bars and better brakes than the 9" ones you have (unless your car was factory equipped with bbp discs) and at least an 8 1/4" A body diff. You'll have to modify your driveshaft too. These are all safety items you need to think about before you turn a wheel.
You could possibly do it all for $1500, but i doubt it. The only thing you could afford new are some gaskets and sealer etc, the nickle and dime stuff.
I would double your budget and you would maybe get there with a used engine etc. and all of the safety stuff included. (rebuilt brakes etc.) You gotta have whoah if you want the go!
Forget about stroker engines for now.
Maybe check out other threads here on this or on bigblockdart.com.
JMHO.
Tom.