- Camshaft timing guides/blocks are used as fastening springs during assembly of camshaft drive pinions when in the timing position
- Services Porsche 996 Turbo
- Use in conjunction with 3891
- Compare to Porsche Factory Tool 9661/1 (000 721 966 11)
Applications include, but may not be limited to:
| Make | Model | Year |
| Porsche | 996 Turbo | 1997-2006 |
| Porsche | 996 Turbo S | 2005-2006 |
