[mysticmissle]

at minimum you are going to send a portion of preheated air thru your radiator with an independent trans cooler in front of it. you may see some efficiency from removing the current tranny fluid cooling capacity out of the radiator however, not sure how to quantify that. not sure how big that tru cool 40k is but you may be able to mount it off to one side where it does not obstruct the air going to the radiator. On my 64 i have a B&M plate style (12''x8''?) off to the passenger side and, and use the brake and have not had any trans failures, but to be fiar i have no idea what my trans temps are. I only know that the cooler off to the side has not effected the cars performance. I am going to be using that car on the street a lot more in its next renditon so only time will tell.
are you experiencing high temperatures now? a lot of users are puttin their coolers under the car or even toward the rear, and using the small fans to cool the fluid. might be something to consider if you have real estate.