I bought a new 70 Z/28 off the show room floor in 1970 and the heater hoses went to the intake and water pump. Those fittings on the alum rad should be for the A/T cooler lines. Cap off the lower rad hose outlet and fill it with water, I'll bet nothing will come out of those small fittings.

 

No, take the plug out of the water pump and run the hose where its supposed to go. post a pic of the radiator.. I am assuming that the line to the rad is not for water, but was meant for trans fluid? Even if it is for water your better off putting it where it belongs on the water pump!

 

Had a.heart.atrack in march.so.jist.got.new.rad.in


stalled had tuff.time.gettn new rad to.fit.in new rad support. I put 4 core with elec fans which made.it.too thick to sit down all.the.way.i had to cut and beat down some of lower lip on core support.
Also pic not correct had to run black wire from relay to thermo switch not the white shown it's got to go to an ignition controlled power source.

 

You beat the heart attack and the radiator problem. Good for you!

 

Dang! What Al said! Hope your doing well and getting all caught up!