I made primer lines to the four aft cylinders using copper tubing basically as shown in the Lycoming O-540 parts manual. I used Lycoming clamps and sleeves, but bought the cylinder nozzles and tees from other sources (for example, Lycoming list price for tee's is about $80 a piece!). I'll connect the aft tee at the bracket to the primer outflow at the firewall using flexible hose.