Routing transmission cooler line questions

[Lonesome7.3]

I am installing an external transmission cooler on my 727 equipped D200. The factory lines run to the radiator and back to the tranny. Is it better have the fluid run through the external cooler first then through the radiator or the other way around?

 

[Cowboy Cadillac]

If its big enough I would bypass radiator entirely and run an external in front of the radiator.

 

[Lonesome7.3]

It came off a Cummins equiped truck with no cooler in the rad. But I still like the added cooling the rad performs.

 

[Cowboy Cadillac]

A large enough aux. cooler in front of the rad will be better than running through the rad first IMO.

 

[Lonesome7.3]

I am guessing this one would most likely be big enough.