Distributor Tester

Years ago I looked over an engine/ compressor in the back of a tire truck. It was a Buick 225 with one special head, so one bank "ran" and the other compressed. All the manuf. did was cut the three unused plug wires, crimp them into a terminal, and ground them to the block

And YES ground them but do NOT leave them open. Leaving high voltage open can be murder on solid state components, and can even damage a coil on a breaker points system. "Flashover", "carbon tracking", etc