Without knowing any specifics about the axle it isn't possible to guarantee a fit for a torsion axle on a trailer with a 3,450 lb GVWR.
The Axle Riser Kit - Single Square Torsion Axle # LC382741 is only designed to fit 3500 Series axles and can be fit whether the axle is a side-mount or top-mount.
The other possibility is you have a Dexter #10 Torflex axle, and for that you would need the Torflex Lift Kit # K71-707-01 as those axles have 2,300 to 4,000-lb capacities. These are compatible... view full answer...