Guy I talked to said they just used regular Pioneer hydraulic couplings in the heater hose(the hot one going TO the heater)uncouple it and couple up to the hose on the cold motor. Cold-motor hose is coupled together and stored on the machine when not in use.

He said this is the most foolproof way nowadays, some new trucks have heater controls that are not easily fooled. This way the cold motor is sure to get flow.