accordinto my chart , 52s came in
4(3/1) spring capacity of 1290lbs 1 1/2" thickness
5(4/1) " " of 1950lbs, 1 7/8" thickness
6(5/1)" " of 1875lbs, 2 1/8" thickness
5(4/1) " " of 2150lbs, 2 1/16" thickness
6(5/1) " " of 2200lbs, 2 1/4" thickness
7(6/1) " " of 2775lbs, 2 11/16" thickness
hope this helps, but ya like sharpe said remove the shortr leafs 1st.