The correct SumoSprings Trailer Helper Springs for a Forest River Salem Hemisphere 273RL are part # TSS-107-40 for 3K-5K axles and part # SS26MV for 5K-8K. In order to find the right kit you simply need to look on the axle tag in the center of the beam for the capacity and then choose the kit that this capacity falls inline with. view full answer...