Stock replacement radiator with extra port?

[white71chevy]

Hey everyone haven't posted in a while but I started doing a ls swap in my 71 c10 that had a 350 th350 combo in it however I was looking at radiators for it and noticed that oreillys replacement one has an extra port that I don't know what it is for. I thought I would see if anyone on here could tell me what it is for and if I could use that port for the steam port on the ls?

[dmjlambert]

On my new Engineered Cooling Products radiator I have the same thing in that position and the website says it is a heater return port with plug.

[white71chevy]

Hmm so could it be used for the steam port then?

[Stocker]

Steam port? I dunno, have not heard of that. As posted above, on my K20 that nipple is for the heater return hose. If a steam port dumps hot water / steam into the coolant then it should work for that.

[Jason Banks]

I had a truck that had one of the heater lines hooked up to that location on the radiator.

[FirstOwner69]

From my observations...
On the earlier trucks, such as my '69 with a 350, the heater return hose ran to a nipple on the right front corner of the intake manifold. Later trucks (maybe '71s and '72s) had the return line run to a port on the radiator as shown in your picture. Perhaps someone with more info can chime in.

[Andy4639]

The extra port is a heater core hook up. Depending on if it had AC are not the heater return went to the radiator on some models.

Yes you could use it for a steam port hook up if you can get the right reducers for the hose fitting.

[darrellyates]

I used it for the "steam port" on my 5.3 ls swap some years ago, and plan on doing the same. Mine ran perfect off that port, got some brass adapters down to a hose nipple. Worked fine.

[white71chevy]

Awesome thanks everyone for the replies being able to use that will make this whole ordeal a lot easier. From some of your responses tho it seems I am calling the vent the wrong term, what should it be called then was always told to make sure it was hooked up to prevent overheating or something along those lines.

[Andy4639]

Originally Posted by white71chevy

Awesome thanks everyone for the replies being able to use that will make this whole ordeal a lot easier. From some of your responses tho it seems I am calling the vent the wrong term, what should it be called then was always told to make sure it was hooked up to prevent overheating or something along those lines.

Port, vent it's all good the same thing.
Just a word on when you fill the motor up with water take the steam port's on the top of the motor loose until you have water coming out then reinstall them. It will be a big help on this. You don't have to take them all the way out but back them off enough to see the water start seeping out. It gets all the air out of the system.

[white71chevy]

Alright thanks for the info I'm sure it'll come in handy.

[Andy4639]

Originally Posted by white71chevy

Alright thanks for the info I'm sure it'll come in handy.

It took me forever to vent mine until I was told! It vented out the ports and I never had any more problems.

[demian5]

on 73 and up square bodies it is used as heater return. I'd use it for that if I had one.

[1972RedNeck]

According to the '72 service manual, that is the heater return port on automatic trucks. On manual trucks, the heater returns to the intake. A/C or not.

[stsalvage]

I hate plastic radiators.They give you a few years of good running But they get eaten up to fast.If you can save the side tanks on your old brass copper radiators do it.They last longer plus when you truck sits for 2-3 years they tends to just need to be rodded out and cleaned and flushed for 100.00.Plus they send to take pressure better then plastic dose over time.Nothing compares to copper and brass Plastic just give it time it will leak clog up or crack

[67 chevelle]

Originally Posted by Andy4639

The extra port is a heater core hook up. Depending on if it had AC are not the heater return went to the radiator on some models.

Yes you could use it for a steam port hook up if you can get the right reducers for the hose fitting.

Agree