[HWYSTR455]

Countersink the bolt into the leafs? No clue what he is saying, but that center bolt on the leafs locates the spring on the perch. The top of the bolt is actually a 'peg', and fits into the hole in the perch. Here's a pic of some standard leaf spring perches. Note the hole in the center where the 'peg' goes through. Some call the 'peg' a centering pin. Those pins come in different lengths depending on the number of leafs, and also come in different diameters. In my case, the pin I used was slightly larger in diameter than the hole in the perch.