Thanks for the info KCS. So I am assuming since I have not added any extra load to the pulleys, no plans for Boost, that I should be fine without pinning it. The stock Damper/Pulley was doing just fine, the darn rubber started to crack and small section has started to deteriorate, fall apart. I also talked to ATI and they said the same thing as you KCS, and that I should be fine without it. Tho, they did try and sell me their $150 pinning drill guide/jig kit.