Really dumb 350 Chevy heater hose question

I have a '78 Chevy E350 chassis with a 350 that I have put on '47 International cab & fenders. I bought an aluminum radiator off ebay that looks really nice, and has the added benefit of a built-in trans cooler (the answer to my question of last week). I'm now working on finishing up the plumbing and can't for the life of me find the 2nd heater hose. I have one coming off the top front of the passenger side intake manifold. I am certain there is not one coming anywhere off the water pump. I've searched everywhere else I can think of and looked at almost every online diagram, and the 2nd one is nowhere to be found. I don't remember when I took it apart where the 2nd one was - is it possible it was off the top of the radiator somehow? For now I'm not going to run a heater, so I just want to loop them together. Any/all help would be much appreciated. I should have my lower radiator hose figured out this afternoon, so I guess I could just fill it with water and 'find it' by starting the engine...

 

A lot of GM vehicles in the 70's had a plug in the water pump, particularly 1/2 and 3/4 ton trucks.

Can you post a picture?

 

There would be a "bung" in the radiator top if that's where the second hose went. My Cadillac has the return heater hose going to the top of the radiator...but I highly doubt Chevy ever came from the factory that way...in every Chevy I've ever seen it goes back to the water pump.

R-

 

Picture would help ,most are in the waterpump.Being that your motor came in a bigger truck it could have been routed to the radiator or even to one of the radiator hoses. Easy fix ,just change the waterpump if it doesn't have the plug.

 

fire it up and see where the water comes out

 

Only two places.
Into the water pump or back to the radiator, should be a bung on passenger side tank about 4" below fill cap and same side as lower hose.

Water pump could have a plug in the top, if so remove it and install hose barb fitting.
If no plug you'll have two good options.
1. Get a pump with a plug
2. Have bung installed in radiator

Other option not as good.
Tee into lower hose.

Bad option
I wouldn't do it because it eliminates the bypass feature but you could just cap off the one hose

 

Yea there is a plug in the water pump. I'm going to see if I can get that out and plumb the other heater hose into that. I got rid of the radiator from the Chevy cuz it was way too wide for the International (last fall - can't remember what it looked like for sure). I bought an aluminum radiator off ebay that was a bolt in for the International (much taller than wide). This new radiator of course doesn't have a place for the heater hose if there ever was one.

Thanks for the help - we'll see if my custom lower radiator hose (two hoses joined by a short piece of muffler pipe) shortly.

 

Like he said, chevy trucks from the 70s-80s had a plug in the water pump, and the return hose went to the radiator. Remove the plug from the water pump, install a fitting, simple.

 

Yep A lot of the Mid 70's GM trucks had the return hose from the heater going to the radiator rather then back to the water pump but the water pump should have a plug in it to put a fitting in.

By the way and E350 is a Ford one ton van and not a Chevrolet truck.

 

Sorry - yes it is a Chevy 1 ton van chassis. Hope to have it at the Iron Invasion - we'll see...