Transmission line locations

[meatbag]

Hey all. So I'm hooking up my th350 lines 76 gmc. I see some that hook right into the radiator and the other circulates through the cooler in front of radiator. I included 2 pics. I'm curious which one yall think I should go with. I just dropped a 454 in it and getting the th350 rebuilt. I'm figuring they can be hooked up either way, but not sure about the benefits. So any thoughts or advice. Please and thank you

 

[85K304SPD]

Either way they go through the radiator. With the auxiliary cooler one of them goes through the radiator, out to the aux. cooler then out to the transmission. If you have the aux. cooler, use it, if you dont, you might want to get one. It might help that TH350 live a little longer behind that 454.

 

[fast 99]

An extra cooler will extend trans life. Have 2 aux coolers plus the OEM in the rad on a Sq B used for towing. That might be excessive for most applications, but one additional cooler won't hurt, 2nd picture.

 

[ChuckN]

Rather than start a new thread, found this one.

When I got my truck, the radiator trans lines were already disconnected. The radiator was shot for the most part anyway, so I had replaced it with a cold case aluminum. I utilized the existing aftermarket cooler that was already there in front of the radiator.

As it is, there are 1/2 lines running to in front of the engine and finished with barb ends to hoses that go to the cooler.

It’s my thought that I’d like to run the hot line first through the external cooler, then around to the radiator, then back to the transmission. Might put less strain on the radiator cooling the motor that way since some heat would have been removed by that time. My guess is that the radiator trans fluid flow is omnidirectional.

So I’d want a new hard line that runs fully to the transmission,and then a fitting to thread into the upper that I can run the cooler hose to. Anyone have any thoughts?

And what is the standard radiator trans line thread size? Thanks in advance.

 

[ChuckN]

Never mind about the thread size- Cold Case website says 5/16 inverted flare.

Still have my ears open if anyone has input as far as flow direction.

 

[75gmck25]

Once it warmed up it doesn’t really make any difference.

Some folks recommend the radiator cooler being the last before it goes back to the transmission, since it may add a little heat to the fluid during warmup and it will flow better when the vehicle is really cold. However, I don’t think transmission fluid ever has any problems with flow.