SuperStock spring tips.

No I mean look at the diagram , the shackle is slanted forward from the bottom attachment point as he described in his post .This made sense to me the first time he posted it , your diagram while pretty has nothing to do with my contention that shimming the front perch with a couple of washers doesn't cause preload to the springs , what it does is slightly alter wheelbase , thrust angle and shackle angle all of which are also very important to launch and weight transfer hence the invention of altered wheelbase {Funny } cars . As long as the axle is suspended with one mounting point being movable you cannot create preload on the springs . Add a 4 link or pannard arm to fix the axle from moving in a longitudinal manner and you create 2 fixed point which you can use to create preload by shortening the span between them thus changing the radius of the spring arc but we're not talking about that sort of suspension are we .