Rear end lurching side to side....

[Jthoms1]

Okay, looking for a little guidance. I just did a full suspension refresh. I bought a used 2002 Boxster S suspension take off (shocks, springs, sway bars). All of the other components were new (control arms, sway bar end links etc.). I had an alignment done at a shop as well.

Car details (anything I can think of that may help) - 1999 Boxster base. Has larger Porsche wheels than the stock with 20mm non-hub centric lightweight spacers (have new hub-centric on the way). Engine was replaced approximately 40k miles ago and I do not know if they put in new engine mounts. I would air on the side of saying they did not as it was done by the previous owner. I have a durametric (really just hooked up first time today)..there are no faults. Engine runs smooth, 5 speed shifts smooth.

Here's what is occurring. When I hit the gas the entire car seems to shift left in the rear and when I let off the gas it seems to shift right. It feels it bit like a swerve when you are in the car. It also happens when you shift. Really any time there is torque applied. Now the suspension refresh may have nothing to do with this. It didn't do it before the refresh that I recall. There is no noise associate with the lurch/swerve.

Anyone have any ideas or troubleshooting steps to check?