Raising the height of a rubber torsion axle trailer isn't as easy as you would think, unless it is a Flexiride axle. The Flexiride torsion arm is adjustable because it is splined. If you have a 10 degree down arm, you could drop in to 30 degrees down and raise the trailer a couple of inches in about 30 minutes. Most rubber torsion axles can't be adjusted like that. In many cases the rubber torsion axle tube is used as part of the trailer frame structure, so if you want to take it off and spacer it down, make sure the blocks are strong enough to support the axle and the flex that may occur. I would suggest a length of structural material welded to the original frame well beyond the front and rear of the rubber torsion axles to spread the load properly.