Yes. But it shouldn't have. Both impellers are in brand new condition.
Differences between the two.
Old impeller is a B- American turbine Aluminum that B1 cut down for me, it was also machiend to set the clearances at .030"
New impeller is a box stock Berkeley C impeller. With much "looser" clearances. Was put in to test top end/crusie and possibly have the AT cut down. But i REALLY dont want to take it apart with how its running right now
Steve-
My experiance has been the opposite-
Berk A2 impy pulled to 5050 (loose pump)
American Turbine AA pulled it down to 4900, 4950 in cooler weather (.012"/side, .017" f-to-r)
American turbine has a sh*tload more holeshot, vs. the Berk A2
(same bowl, diverter, etc)
Very interesting findings.
Dan'l