What size tranny cooler do I need?

[ErrabundusBus]

I would like to tow my Astro van behind my DT360 equipped Skoolie. I think it'd be best to add a transmission cooler. Any thoughts on how big of one I should look for? Any ideas on what to look for at a salvage yard if I were to go with a used one? We are planning to make a run down to Gulf Shores Alabama in about a month. We were going to take our bicycles but now my wife is expecting #6 so it'd be a little uncomfortable for her, hence towing the mini van.

[the_experience03]

Buy the biggest NEW one you can get. Tranny coolers are a bugger to get really clean. Mount it in series and ahead of the stock one in the radiator. This will allow the cooler to dump most of the heat, but will allow the coolant to bring the fluid back UP to a decent operating temp when it's really cold out. Cold tranny fluid isn't any better than hot tranny fluid.