Noisy & growling variable assist power steering

[95CSC]

Hello. I recently purchased a 1995 Cutlass Supreme Convertible with a 3.4L engine and variable assist steering, knowing it had a growl in the power steering pump. It is a great looking car and fun to drive so I want to get the steering fixed ASAP, but it has been more of a challenge than expected. Basically the low pressure hose was weeping and the high pressure hose looked old, so I replaced the rubber sections of the low pressure hose and installed a new high pressure hose. I also replaced the power steering pump twice and bled the system extensively until no foaming or bubbles were present. This did not fix the noise which gets louder the longer the car runs. It almost appears that the pump pressure is getting so high it is cavitating but no air is present in the system. Thinking it may be the EVO valve I went to the local junk yard and pulled one from a 1995 Grand Prix GTP with the same engine setup. This did not help the situation either. I also noticed that the valve itself (which is on the high pressure hose inlet) and the return hose get so hot you can barely touch them. The noise will happen regardless if whether I have the electrical connector, connected to the EVO valve or not. I am wondering whether I have a restriction within the rack & pinion causing the pressure to back up to the pump and causing the noise or whether the valve itself is causing the issue even when not plugged in. Any thoughts or suggestions? Any help would be appreciated...

[1990lumina]

When you bleed the system I'm assuming you are doing so with the engine off.

[95CSC]

Yes, With the front end off the ground, engine off, moving steering wheel completely in both directions 20 to 40 times. Then I start the car do it again about 10 times with the engine running... The fluid does not look like there is air in the system, no bubbles and it is not milky, but yet the EVO valve gets hot and so does the return line. The noise gets louder the longer the car runs and warms up.