Welcome to the site. I prefer the balance of a small block in an a body than a big block myself and I don't make my knuckles bleed trying to get a big block set up in the car. The 4 speed parts gathering can get expensive and you will have about $1500 in just parts. They make adapter mounts for any engine in your /6 k frame so you just need to figure out which one you really want. I would also upgrade to disc brakes if you like stopping. We can help you make a list of what you need for your build once you figure out the drivetrain set up.