440 or built 360 71 demon

You really need to define what you want out of your powerplant. There are guys that run pretty healthy and drivable 360s that can run 10s or 11s...there are also guys that just want the mystique of popping the hood at looking at a big block, even if it is stock. If you just want a stock big block, you'll still need to get the mounts, trans, exhaust, cooling system, and unless you don't mind riding on overtaxed suspension, some new t-bars might be in order...and that's just the big parts. Also need to take into consideration what ancillaries you want to run, induction, ignition, etc...unless you buy a complete running big block car and part it out for your project, you'll be acquiring a pretty big parts list.