Thank you for the photo and all of your information, it really helps to narrow down what you will need!
It looks like your 2010 Starcraft 1223 Popup Camper uses a single #10 Torflex axle which means you can use the Torflex Lift Kit - Single Axle - 2-5/8" Lift # K71-707-01 for your application.
The only exceptions to this fitting your camper is if your torsion axle is top-mounted or if it has 3" high profile brackets or Norco brackets. view full answer...