Brother of The Benz, Tompkins
Sorry for so long replying as Joan, our Benz and I were in New Mexico.
It sounds as if you are in a state of ????
Any pump that would physically fit and the belt grooves align will do the job. As for belt contact, if you look at your belts pathe of travel you will see there is minimal circumferencial contat.
There is very small load on the pump except when you turn the wheel to the right and left stops. Then the pump puts out it's max pressure and you may get a belt squeel.
Now for the consequences; if the pully diameter is different the only change would be pump speed.
As speed changes you may have normal pressure at a different engine speed and I can't imagine what difference that would make.
As an old fool I would say if it fits use it.
Happy Trails Beep Beep from The Spiderman in Houston!!!