SPU cartridges and washers


Hi,
I am using an SPU Synergy G II with a Sorane SA 1.2 tonearm and wanted to get advice please about using a washer between the SPU and the tonearm socket. I bought the SPU new from an Ortofon dealer and apart from a sticker on the box saying SPU Synergy G II there is no specific information about how to use this cartridge. Even the range for VTF until recently said 2.5 - 3.5g and is now changed to 3.0 - 4.0g in Ortofon's literature ...?
128x128rogerstaton