Question: are you going to run with a stock /6, 273, 318 or are you going to make more power. If keeping it stock you can do the drilling of spindles.
I always upgrade to 73-76 disc set up with manual brakes for stock /6 or more HP, next thing is use 15in wheels due to more selection of wheels or tires and your set. You can always find factory parts if needed another day. remember keep it simple and have fun with the project.