Thager-- That is for the 2 outlet model. The high output heater core is 1 3/4" longer so they may use that for the 3 outlet model. But that is just a guess on my part. I found out that Heatercraft changed the cores and suppliers for their cores in 04 and the old and new cores are not interchangeable. The new cores do look more robust but i would need to buy a whole new unit (Ski dim has the 2 holer for $110.00), since I'm in TX and don't use it all that often the $24 seemed to make more sense. Plus I would have to re-drill to install the new box style.