I got a new battery and ever since its been cold out it has been hard to start. it cranks good but it takes it 2 or three times to finally start and stay running. once the truck has been ran it is fine. could it be the battery. its a 4.2 by the way

 

I'm not sure about the 4.2L but I know on the 5.4L's there were some issues with dirty IAC (idle air control) which is attached to the back side of the throttle body. I had problems with mine starting, turned over great but took a few tried to start it. Pulled the IAC, cleaned it with intake cleaner, reinstalled and never had a problem since. Also helps smooth out your idle.