440 under car headers need advice.

One thing worth noting on the power steering or no power steering question; what is the steering box ratio with the manual box? IDK the answer but I know on most cars the ratio is slower with the manual box to help reduce the amount of effort without the power assist. That means that an emergency evasive maneuver will be slower. You know when the pinhead in the Prius suddenly pops the nose of their shitbox into your path and you have to quickly steer around it to avoid a collision. It's something to consider. I look at this debate pretty much the same as a debate about leaving the 9 inch non-power drums on the car or upgrading to better brakes. In the end it's to each his own.