On a 1986 305 Chevy van, the ignition coil is typically located on the passenger side (right side) of the engine, near the firewall. The boot will be the rubber cap directly on top of the coil where the high-voltage wire connects to send electricity to the distributor. There's only *one* boot on the coil itself; the high-voltage wires then run from the distributor cap to the individual spark plugs.
To be absolutely certain, you should consult a repair manual specific to your 1986 Chevy van with the 305 engine. A Haynes or Chilton manual will show you a diagram and detailed location. A visual inspection of your engine bay will also help – look for a relatively small, cylindrical component near the firewall with a single, thick wire connected to a rubber boot on its top.
