67 Barracuda Big Block K frame keep it or change it ??

He said "power steering and brakes" which I assume meant power brakes. Does the vacuum brake booster fit w/ big block? How does aftermarket k member change available space at firewall? We can't just poke a 5 course meal in the Scooby Doo lunch box. Where theres a will theres a way... electric power steering? hydro boost brake assist?
If I had a OEM big block build and wanted all those "side dishes" I would buy, or trade for, another car. A slant 6 build offers ample space for headers and anything else you desire, less meat and more taters LOL