I have a buddy who has a Calspa and so do I. My tub has a bigger pump and outlets (2 inch I think). I put a new pump in mine and it didn't fix the problem so I gave the old one to him. If this pump is 1HP bigger and the old pump will fit on the motor will it hurt anything?

Don't really understand the question, however - if you've got a 1 hp wet end on a 4 hp motor, no harm no foul.

Be very careful putting a larger pump in. We went from a 2hp to a 5hp and it caused my inline pressurized canister to crack. it will also cause cavatation to some flex lines. Remenber it is the size of the impellor that gives you more pressure, not just the size of the motor. Good luck with the Cal-spa.