To determine if you need to use the spacer, please do the following:
Fit the Suspension without the spacer and when the Suspension is aired out, check whether the swing arm rests fully on the bump stops.
If the swing arm isn’t resting on the bump stops when aired out, please add the 1/4″ spacer.
Please Note: When fitting the SAS-99 Kit to a Genuine Harley-Davidson 1989-99 Softail Frame, the 1/4″ Spacer is required.