The easiest way to check is to look at the frame immediately above the area where the axle
is mounted to the trailer frame. There should be doubled-up welded-on extra square channel tube attached below the main 3" C channel frame rails directly above the axle
. These sections will only be a couple of feet long. If you don't have the added 1 1/2" short sections attached under the main frame, then you don't have the high-lift axle
. If you see those 1 1/2" square channels welded under the frame and above the axle itself, then you do have the high-lift axle.