98 challenger 1800 cavatation or not?

[adefiore]

When I throttle up from a stop the left engine will pull until about 4000 RPM and then it will rev to 7000 if I keep accelerating it will grap again and continue fine to redline. I though this was a wear ring problem, but I changed wear rings and a new impeller and I am having the same problem. What else could be making this happen?

Thanks
Anthony