Here are the
H&R wheel spacer part numbers for:
15mm DRS - part # 3065662 (DRS is stud replacement)
20mm DRS - part # 4065662 (DRS is stud replacement)
25mm DRM - part # 5065662 (DRM is bolt on)
H&R mfg web link:
2003 Nissan 350Z Applications || H&R Special Springs, LP
The sport rims for the 370Z have the same bolt pattern as the 350Z.
The best source and pricing I have found is through one of our sponsored vendors.
Stillen: contact Josh@Stillen on this forum for some killer prices and top notch service.