I want to verify how my external trans cooler is hooked up. Can someone tell me which trans cooler line is the returning cool side and which is the outgoing hot side? Looking at the transmission (TH350) where the two coolant lines connect there is an upper line and a lower line. Is the lower side the hot side going to radiator?

top line on the case is return, if I remember correctly.

hot oil should go in the top of the radiator and cool oil returning from the bottom of the radiator

Absolutely, that part I would agree with, the hot oil going into top or rad and cool coming out at bottom. It's the trans side I am unsure of. It would seem to make sense the oil pumped out of the trans would be the lower but if anyone else could confirm?

Correct.
Lower line exiting from transmission is hot fluid pumped to upper fitting on radiator to be cooled.
Cooled fluid then exits from radiator using lower line and returns to trans thru upper fitting.

excellent thank you

I finally received the new radiator. I noticed the filler neck is installed on the top and concerned me that it might interfere with the hood. My current rad. is at a 45 degree angle. Dewitt's tells me the top mount was standard and they have had no complaints with other Chevelle owners and that the filler neck at a 45 degree angle started with 73 Chevelle's. That I know is not true. Whether or not I have a problem with it fitting I won't know until I check.

I have no interference issues with my car.

My 70 is on a angle.

Carpool- that's a stock radiator with that top mount neck? I placed the radiator temporarily in place last night and it surprisingly clears. But only by a hair. DeWitt's says they can swap out the radiator if I wish which is pretty decent of them. Not sure what I want to do now.

Mine is also angled

http://i777.photobucket.com/albums/y...rontBumper.jpg