Flying "K" vps to ewr. No First out of vps but is on MD-88 atl-ewr. Mid aft Wed flight.

How far in advance may I request that I be put on the paid upgrade list for first from atl to ewr? I only have 49 minutes in atl to change planes/concourses. Perhaps too close to obtain an upgrade?

Can't find the answer on DL.com.

Thanks.