440 under car headers need advice.

I'm kind of surprised at how willing a lot of people are to get rid of the power steering on a street cars in order to fit parts like headers for performance gains. I've never driven an A body, let alone a big block A body with out power steering but I had a GTO with a big block Chevy and a Firebird with a Pontiac 350, both with manual steering and both were a real pain to drive in the pits at the track or parking lots or any slow speed maneuvering. For me PS is a must have on a street car, its makes the car much more enjoyable and it adds points or creed to build a car that runs hard without resorting to removing amenities to get there. To each his own. My advice is to keep the PS, you won't regret it.

What if your car was manual steering to begin with?

A big block a body with manual steering is no big deal. If you switch to as rack it's even easier to steer. My wife drives mine.