The purge solenoid is attached towards the front of the left fuel rail. I'm sorry but I don't have access to part numbers.
I'm sorry, the code P0449 is actually for the vent solenoid and not the purge solenoid. There is alot of confusion between the two. The vent solenoid is located and attached to the rear of the gas tank close to the driveshaft (some vehicles may have it above the spare tire). You may have to crawl under the vehicle to see it. The ac-delco part number for this part is 25950499. Here is the repair procedure for the vent solenoid. I hope you can see the pictures.
Important Clean all evaporative emission (EVAP) line connections and surrounding areas prior to disconnecting, in order to avoid possible EVAP system contamination.
Here is a part number you can try. Ac-delco part #(NNN) NNN-NNNN