Salinda,

I think that my pressure increase is because my old pump was "plumb wore out".

I didn't see any damage inside the old pump head, so I can't give you any technical reasons for the increase other than it must be a combination of the old pump being worn-out and the new pump being vastly superior in efficiency.

If your 2 hp is fairly new, I would expect that it is operating closely to its pump curve, and that a comparison between the old pump curve and the new pump curve will tell you what to expect in terms of any pressure increase/decrease.

HTH,

pj