1983 GMC cooling system.

[Swed-Chevy]

Hi,i need to replace the radiator who is leaking.Om my car both hoses
to the heater core for cab came from the engine,one from manifold and one
to the water pump.

But was thinking one off these hoses maybe should be connected to the radiator original ??

[motornut]

Hi ,i find you get better/heat sooner
up here I think thats the better way
If you are spending more time getting heat out of the cab,
one from the rad(southern temps)

[gchemist]

Mine had the return going directly into the radiator. My aftermarket intake supplies the heater core. From a dead cold start, in less than 1 mile, heat is coming out!!

[Swed-Chevy]

Thanks for your anwers.It,s about -70 F here now so i wait with the radiator mod.The radiator works yet but leaking a litte just under upper connection to thermostat.

[gchemist]

You can run the heater return to the water pump. Supply is more important. The closer to the thermostat, the better. You live in a very cold climate, running the return to the water pump is better. If you do route return to the radiator, route it to the left side (lower radiator hose to the water pump).

[motornut]

Originally Posted by Swed-Chevy

Thanks for your anwers.It,s about -70 F here now so i wait with the radiator mod.The radiator works yet but leaking a litte just under upper connection to thermostat.

-70F? may want to (block heater) plug it in...
make sure your mix is good down low too
no leaks even better heat,you will end up with air pockets

[Swed-Chevy]

A couple of years ago it was -88 F for a week so the mixture of anti freeze are very important.All our 5 water cooled vehicles have block heaters and the cars we use most also electrical cab heaters.