You know I forgot but I bought my 3400 lb SS springs from Mancini for my 63 and it sat a bit lower then I thought it would. Here is how it sits after I raised the back about 1" by using different rear shackles and my rear tires are Hoosier 30 x 9's. After I put the shackles on to the height I like I cut them off right at the bottom of the shackle as I hate to see 6 inches of shackle hanging down below the spring in the back of the car. Ron