The whole system holds less than a quart of fluid. I'm thinking only about half a quart.
As I've had a bit of practice bleeding this system. I'll share my method with you. Fill resivor near full, leave the cap off. Remove cotter pin and nut from the end of the ram. Push shaft slowly all the way in untill it hits the stop. Then, pull the shaft slowly all the way out until it hits the stop. You'll hear bubbles in the resivor as you do this. Check the level in the resivor. You don't want it to go empty. But at this point keep it at or near the cold level. Push the rod slowly in again. Still hear bubbles? Pull slowly all the way to the stop again. Doing this moves the rod the full length of its travel and thus pushes air out. The turn the wheel from lock to lock method that most people use never has the rod go all the way to it's internal stops. Thus allowing a small amount of air to remain. By slowly pushing the rod all the way to internal stops you generally will have it perfectly bleed in about 3 cycles without even starting the car. Set fluid level to cold level with the rod reconnected nut tight and cotter pin in place. Put the cap on tight and go for a drive. Changing hoses should not require readjusting the control valve.

 

When we bought our '78 in 1990 it seemed to leaking P/S fluid from everywhere! Once cleaned it was clear that it was only the return hose, which was replaced. Over the ensuing 34 years I've probably changed the hoses about 3 times, usually in sets and more as a preventative measure, apart from on one occasion when a hose let go as I was putting car away after a 2000 mile long weekend! That last change was a few years ago when I re-built the PSCV valve, again a full set, mainly for the aesthetics of having everything looking new!

When changing the pump-to-valve hoses I remove both, taking the inlet hose off first as it is on the "outside" of the valve (as you work on it through the wheel arch). I re-assemble in reverse, starting with the outlet, as it makes it much easier to tighten the flare nut on that before the inlet hose goes into place.

I used to find it hard to get the flare nuts to seal until a mechanic friend suggested PTFE tape. Now I always put a turn or two of PTFE on the threads and they seal perfectly, without the need to wind on tons of torque!

Like 4-vettes, I bought myself a good set of flare nut spanners early on, and they are essential for so many things on the Corvette.

I also do not follow the prescribed procedure for bleeding the P/S system, which involves starting the engine. I simply have the front wheels off the ground, fill the reservoir, then turn the steering wheel slowly from lock to lock about 6 times. I check and re-fill the reservoir and turn the wheel lock to lock again about 5 or 6 times, then check and re-fill if necessary.

It shouldn't be necessary to adjust the PSCV after a simple hose change.