Saginaw power steering pumps

[cj847]

I am having an issue with saginaw pumps. I have replaced dozens over the years without an issue.

The issue: Pump is on an LS swap. It is a 2001 hydroboost pump. It was not producing enough pressure to make the power steering feel right. It is better than non power, but not nearly as easy as power steering. So, I bought a rebuilt unit and it felt about the same. Then I pulled it off and "hotrodded" it like the offroad guys do (2 #4 flat washers under the relief valve spring). Literally no change.
PS> It has a new steering box and new hoses.

I guess I am looking for ideas. I am considering:
-buy a pump for an 86 c10
-buy a high dollar aftermarket pump like borgeson or others.

What do the experts say?