Planned Delivery Time from Material Master instead of PIRs

Hi SAP Gurus,

Do you know if there is a way to have MRP look at the Planned Delivery Time from the Material Master (MRP 2 tab) instead of the PIR?

We would like to create global PIRs with a PDT of 1 and have the Material Master PDT set to a different number (example 5).  So when MRP runs it will read 5 instead of 1.

Any additional information is appreciated.

Thank you

-nic