As far as I know the SR does not have a harmonic balancer, I had just a crank pulley on my highport. Even the mechanic who put on my UR pulleys for me (I was once a newblet with wrenches) asked where the balancer was. I do know there are some aftermarket harmonic dampeners for us though. One is from ATI ($400ish), another is from powerbond ($300ish), and Ross ($550ish).