the oil filter micron thread got me thinking about transmission coolers. why, i don't have a clue, but anyway, here goes.

i have two coolers here, both 3/8" tube inlet/outlet size.
one is 12"x4"x1 1/2" thick, and is a "two pass" [just in, loop around, and out].
the other is 12"x11"x1 1/2" thick and is a six pass.
both are aluminum and use 3/4" tubes with aluminum fins in somewhat of the size of a radiator.

the question is, could the small one be used as a stand alone cooler for a 727/reverse manual 3800/4000 stall converter, heavy street/occasional strip car, or should i use the larger one ?
if i use the larger one, i have a [single] fan from a 90's minivan that fits perfectly, i could use if needed.
stand alone in a good airflow is the key, as the radiator to be used does not have an in tank cooler.

your opinions please, are greatly appreciated !
as always, TIA !

Do you have a trans temp gauge installed in the tranny?
If so try the little one first and see what it runs with it
I've made the mistake of using one that is to big and the tranny temps never got above140F ATF needs to be at least 160F for the additives to work according to the engineers at Torco years ago

operating temperature was something i was wondering about, so i need to get a deep aluminum pan first, then put a temperature gauge in.
i'm thinking the little one might work with that pan better than a stock steel pan or a [somewhat] deeper A518 pan.
i was also thinking about mounting it under the car to make plumbing easier.

As Cab says, without knowing the temps, it's a guess.
But location/airflow obviously matters; I like 'em behind the grille, and use as much hard line as possible.
I'm inclined to think the 2-pass is too small for that application.
Buddy ran a high-stall drag-only car, about 8x8 multi-pass cooler on firewall with a fan, and it was marginal.
Crutched it with synthetic fluid.

Dominic, Thumperdart , put a small single row aluminum tube type cooler in front of his radiator on his Dart years ago and ended up moving it and put it behind the front bumper mounted horizontal so the tranny fluid would run between 160 and 200 F in the summer time in the Mojave desert
Try the deep aluminum pan first with the temp. gauge and go from there
I use the stock tranny coolers in the radiators if they have one, they actually will help keep the temps up in the winters
I think one of the guys on here ended up using two tranny temp senders when testing coolers on his street and strip race car, one sender in the pan and one in the front output cooler line going to the cooler, I think he saw around a 40 degree differences when using the cooler with the cover off. 190 leaving the tranny going to the cooler and 150 F in the tranny pan with the sender in the rear of the pan
IHTHs

Unless you're pulling a trailer for miles in the summertime. the small one.

Cooler size is 100% dependent on use. If the car is rarely driven then it doesn't need much of a cooler. Most street/strip cars don't need much of a cooler since they typically are not driven very hard. As soon as you start doing a lot of WOT driving, or towing or hill climbing then you need a big cooler. If you don't have a tranny temp gauge then you don't know what you need. I had a temp gauge channel on my data logger in the Duster and the tranny temp was always cold when cruising around town. Only time it started to get any heat in it was freeway driving and then only after about 20 miles. But if you went WOT going up a long hill on the freeway then the temp would climb pretty fast.

I'm watching this topic while waiting for my converter

THERE you go ! .... unless the temp of the ATF has a factor of the up shifting or the torque converter operation......

And seaBee .... mopX has a tranny ??!! ... I always thought he was a STRAIGHT SHOOTER!

Cab, i am going to use one temperature gauge with two senders, one in the pan and one in the output line as has been stated, then switch between the two to observe the difference.
the radiator does not have a cooler in the tank, therefor the size question.
no towing, and no wintertime use, so no problems to crop up with those two scenarios.
also, the only flex line to be used will be from the hard lines connected to the cooler.
depending on how/where i mount the cooler is the next item to think about.
use the small one if mounted up front in the air stream, and the big one if mounted under the car ? either one will be mounted horizontally.
thanks for the replies fellows !

Go for a nice ride then shoot your converter with a temp gun, then you will know which cooler to use.