I used to pin them but found there's no way they are moving. It's a hard press to get them in, 8 tons or so.
My concern with that is the amount the receiving sleeve in the arm stretches when pressing that hard. This became very obvious when doing Whiteline bushings the first time and I pressed one back out so I could realign it slightly. Very little force was required to press it in the second time. I pushed it back out and tried a new bushing and it too went in easily, so the arm had stretched. It’s quite possible that if properly aligned the first time and left in that would never be a problem, but I decided to pin them all anyway.
This reminds me, at the same time I discovered that even brand new long-bolts for the upper arms are not always perfectly straight, making perfect alignment of solid bushings a bit trickier. Has anyone else encountered that?