> I have a question related to the original Mazda heater core configuration:
> How was it connected? There is a 5/8 or 3/4 water connection on the rear
> iron but there is no mating connection anywhere. The water pump has a
> small
> 3/8 connection that feeds into the original intake system. Was there a "Y"
> in the water pump outlet to radiator or what?

The 5/8" outlet on the rear iron is the output to the heater core. The
return from the heater core can go anywhere you want as long as it is on the
suction side of the water pump. My return from the heater core goes into the
bottom of the radiator. It could also be Tee'd into the radiator hose if
that's easier.

Joe Hull
Cozy Mk-IV N31CZ (65 hrs - Rotary 13B NA)
Redmond (Seattle), Washington