I want to raise my trailer a few inch's my leaf springs are already on top of the axle is blocks the answer to get it higher, already lowered the hitch to max bed to trailer height.
You need what's commonly referred to as a sub-frame, which is just pieces of square hollow stock about 6-8' long welded to the bottom of the frame, to which the spring shackles are attached. The rise is determined by the thickness of the square stock.