Welcome to CHR! If you like the power of a big block, I doubt you'd be happy with a 327. They were a great engine in their day, but they have to be built to take a lot of 7,000 RPM and up use to make decent power! A small block stroker motor, 383 or even all the way out to 427 will make great torque at mid level RPM. Many drag racers are using Powerglides, but it takes big bucks to make them "live" behind big power engines! For street use the automatics with overdrives, like the 700R4 will retain a low gear ratio for launch then give you that extra overdrive ratio for cruising on the highway. If it's all about nostalgia, maybe just make the old 327 all pretty and leave it on a stand in the shop and build a big inch small block or big block for the car. Whether or not a project is worth the time and money it takes to do it right is strictly in the eye of the owner!