Transmission cooler Qs

[davepl]

Even though I'm otherwise doing a very stock restoration, I'd like to add a transmission cooler. I have a few thoughts about it that I'd like to bring up for discussion, sort of to "check my math". There's a couple of questions inline here too...

- I want to use all hard lines, no barbed fittings or rubber hose. I figured I'd custom bend lines from the transmission to the aux cooler to the radiator and back to the transmission.

- Does anyone know authoritatively how I tell which of the two fittings on a transmission (TH400 or possibly 200-4R) is the -output- and which is the input? I've always assumed the low one is output, but can't find proof.

- I've found a few B&M stacked plate coolers that have 1/2 NPT fittings. Is this the same size as the stock transmission cooler line connections?

- I plan to run the coolant through the aux cooler first and THEN through the factory rad.

My rationale for this last point is that I grew up in a very cold region, and while that's not as true here, I figure that having the factory in-radiator cooler last will serve to -heat- the fluid up a little (on purpose) on cold days. With a 180F thermostat I was not able to find any proof that colder trans temps than that provide any real benefit.

The oxidation rate of a hydrocarbon fluid doubles every 20F over 175F, but I have to figure that running cold fluid isn't great for it either.

And lastly, other than making custom bracketry, is there a clever way to mount a transmission cooler in front of the AC condensor or rad OTHER than the plastic "pull them through the core fins and cut em off" approach?

Thanks!
Dave

[davepl]

I'll answer my own question about which line is which in case it's useful for other folks some day:

MANUFACTURER TRANSMISSION MODELS TRANS RETURN LINE INLET
ON THE TRANSMISSION

General Motors TH125 / TH125C / 3T40 Top
General Motors TH180 Rear
General Motors TH200 / TH200-4R Bottom
General Motors TH325 / TH325-4L Top
General Motors TH350 / TH350C Top
General Motors TH400 / 3L80 / 3L80H Top
General Motors 440-T4 / 4T60 / 4T60E Horizontal Fitting
General Motors 700-R4 / 4L60 / 4L60E Top
General Motors ST300 Top
General Motors 4T80E Main case
General Motors 4L80E Lower front
General Motors TH425 Outer, farthest from Torq. Conv.
General Motors MX17 Bottom
General Motors A130L Bottom
General Motors F3A Bottom
General Motors Aluminum Powerglide Top

[DPowers]

On my '66, I tucked it up under and behind the front bumper and used braided lines.

[mcmlxix]

My .02 cents:: Even factory lines use some soft line at some point. If the trans/motor twists opposite to the frame/radiator support, eventually the hard line will fail. The line needs somewhere to flex....

[TobyArnot]

Don't want to hijack thread, but could this all be done with soft hose (i.e. rubber) as opposed to hard lines?

Thanks!