When I bought my 87, the previous owner had the heater core fail on him. He bypassed the core, but did it in a way that left the hoses clamped to the failed core. What he did was run the 3/4 return hose (number 7 in the diagram) directly to the throttle body. At the throttle body, he took the tb hose (number 3 in the diagram) and used a plastic valve to join it with the 3/4 return line from the radiator. This bypassed all of the stock diverter valve and left it intact. I am going to correctly route the hoses this afternoon, but am wondering what kind of effect this re-routing of hoses can have on horsepower or general operation of the vehicle. What do you guys think?

 

Just put it back the way its in the figure with or without the valve and just bypass the throttle body. You dont need that hot coolant running through the throttle body.

 

Just plug the radiator nipple and the nipple on the intake manifold and your all set. Get rid of all the hoses then.

 

I apologize for reviving an old post. I am helping a friend to bypass his heater core. I wanted to know where on the throttle body the 3/4 return hose (number 7 is connected to, since the 3/4 line (number 3) is connected to it?