I want to install a transmission cooler for a 2000 Chevy Silverado w
5.3L w/ 4L60E. I googled how to do this and there's a lot of
contradicting info. Some say get the largest cooler you can and
completely bypass the in-radiator cooler. Others say go trans to
radiator, radiator to cooler, cooler back to trans. Then some also
say go trans to cooler, cooler to radiator and then radiator back to
trans. I guess this method is to "preheat" the trans fluid in cold
temps? I have not seen any mention of a thermostat other than
operating a fan on the cooler itself.

Do I even need a cooler? I am in the Denver area and tow a 7000lb
trailer 500-1000 miles a year, mostly in the summer. I read the 4L60E
has cooling issues so I never tow in OD and change my fluid/filter
every 20k miles. If I do need one, can I just bypass my radiator
completely? On an old Buick, the internal radiator trans cooler
leaked and circulated trans fluid through the cooling system which was
the beginning of the end for that car and I'd like to avoid that on my
truck if it's safe to do so.

TIA!