Please Help with Trigonometry (and maybe measurements)

So I plan to install some Alcans leafs tomorrow after work, and really want to have some 3 degree shims on hand. Due to piss poor planning, my best bet to acquire these on short notice is to have a local machine shop fab them for me out of some bar steel. I'll attach my current schematic below. My main question is if anyone has a measurement handy for how long (from front to back they should be). I want it to run essentially the whole length of the perch (assuming it's around 4-5".

That will help me complete my trigonometry equation to know the height on the higher end (using tangent of 3 degrees = x [number I'm solving for] / length).

If you also have the diameter of the center hole it will need (same diameter as the hole in top of the leaf spring perch), that to would be greatly appreciated.

Stuck at work and won't have time to go home for these measurements before needing to get to the steel shop and then to the machine shop before 5, so these measurements could really help me out. TIA.

 

I would only install the shims if you have vibration issues. In fact, you may be installing the wrong shims without measuring your angles after the leaf goes in.