1.5" Progressive AAL install question

So i have everything to do my lift, just waiting on toyota to do my frame swap first then im installing everything. For the rear i am going to use the headstrong 1.5" progressive AAL.

When i orderd the AAL, i was advised that i should install center pin head lengtheners (http://www.headstrongoffroad.com/st...nter_Pin_Head_Lengtheners_(PAIR)_-_CBHL1.html) so if i need to add rear axle shims i will be able to install them more easily. My question is how do these work? do i just slip it over the center pin so its on the bottom of the leaf pack and then i just install and tighten up the u bolts and if i need to add a shim i just loosen the u bolts up a little bit, slide in the shim, and call it good? If i dont need to shim the rear do i just leave it be and call it a day?

Also if anyone has a link to a write up on installing the 1.5" AAL it would be appreciated as a quick search turned up no results.

 

https://www.tacomaworld.com/threads/aal-install-second-gen.54186/

The suspension forum has a lot of great info about all things relating to lifts.