the tube down low on the side of the rear housing, coolant exits engine from there and goes into the heater core. can be blocked off if no heater will be used. the others can be blocked off as well since it's running a carb. top of rear housing is coolant exit going into the intake/throttle body, then back in behind the w/p. i'm guessing on the latter as i'm not that familiar with the 86 and later engines. if u search the forum u will find answers/ideas on how to deal with the 5th and 6th port actuators, and many other things concerning the rotary. many have been down this road.