I changed the plugs, cap and rotor on my 31 signature with twin mercuiser 5.0 MPI this week. The plugs next to the vaccuflush unit weren’t fun to get to. On the port side I had to reach around the generator and hot water heater. The starboard rotor and cap weren’t bad, the port side was brutal. The screws for the rotor are maybe a quarter inch long and non magnetic with T15 heads. It took me five hours to complete the job. I wonder what the mechanic would charge?