1 bolt & 3 bolt cams

Off topic a little, but I bought a small Isky roller cam (R505-T) for a BB sight-unseen, and when it came in, it was single bolt. Also it was a cast core, so it needs no bronze intermediate shaft gear, perfect for the street. But how do you control the thrust, when a thrust button/roller would go where the central bolt is? I figured out a solution but haven't tried it yet. Thanks McMaster/Carr. LOL