andem Trailer Axle Suspension Rebuild Kit with EQ-356 6-1/8" Equalizers,Part Number: SRK-TA-SB-356E Tandem Trailer Axle Suspension Rebuild Kit with EQ-356 6-1/8" Equalizers,Part Number: SRK-TA-SB-356E. This is a kit to change all the "wear parts" on a standard tandem axle trailer (3,500# GVW up to 14,000# GVW) . This is for standard "Eye to Eye " Springs, not "slipper" springs (bolt on one end of spring only),For standard 1 3/4" wide springs. Hole Center to Hole Center from Top Hole to either side hole is 2.50" Hole Center to Hole Center from Side Holes is 6-1/8". Kit Contains:14- 9/16" x 3" Shackle Bolts,14- 9/16" locking 9/16" nuts,2 - Center spring pivot equalizers, 6-1/8" bolt to bolt wide,14 (6 are already installed in the equalizers)- New Nylon Spring Bushings,8 - New Spring Shackle Straps 2.562" center hole to center hole.