swap power steering help

[azsmokey]

I have a question that I hope someone might be able to answer. We swapped a 6.0l into our 72 K10 and most everything works great. The issue we are having relates to the power steering. We installed a new gearbox during the build and the power steering worked great on the donor vehicle prior to disassembly. During testing in the 72, the steering was next to impossible to move when the vehicle was at rest and generally ok while in motion, although requiring much more effort. The pump was inspected and is operating nominally. A local shop suggested an adjustable pressure valve which enabled the steering to function very well at rest, however now while in motion, the steering is very loose and apparently "over-powered." Has anyone had similar issues when completing the swap? Thanks for any help.