Shin Sanbongi and Guy Mariano, despite having stark differences in trick/spot selection both share one commonality. They both appear to only use 2 bolts per truck (diagonally of course). They are not the only pros that do this.
Why? I asked the same thing so I tried it myself, only to find my trucks hella loose-feeling after a while since the bolts came a bit loose (suppose I could tighten them more), and kinda made me feel unstable and paranoid my shit was about to fall apart.
So now I must ask you, why? or is it more of a "why not"?