If you choose to undertake auto repairs to your Polini 911 GP4 then it is always a great idea to have access to a Workshop Manual to keep just for reference in the event that you need to know ways to remove a specific component much like the Brake Discs and match it again appropriately.
Polini 911 GP4 Workshop Manuals are able to offer specific diagnostic guidelines with regards to your car or truck so if something is broken it can help you understand what the problem is and the best way to repair it. You will be able to decide if this can be done by yourself or in the event the job is just too big you could book your 911 GP4 in with a local mechanic.
Polini 911 GP4 manual