Leon - for sure the designs in the stovebolt era were 99% lowest cost, but cheapest vs best is a trade off, and sometimes may be fixed upon by accident .... Ford in 99 changed from a rad trans cooler to a separate one in at least some trucks, was it better or were they trying to save a few bucks? - in 2000 they switched back after dealing with too many fried transmissions
my understanding of the heat problem is the more rapid breakdown of the trans oil to the point of no longer lubricating properly - all the info I've seen indicates a "useful lifetime" of the oil for a range of temperatures and recommendations for changing fluid vary with observed operating temps - I've been researching this extensively, which is why I recommend a temp gauge and paying attention to it
the primary project I'm concerned with is a 4L80 in a highway coach that way predates in-rad trans coolers - it will have generous standalone cooling with thermal controls for cold bypass, which some aftermarket coolers offer and can be had separately - my concern with the linked cooler is the lack of a GVW rating, while there are a number of companies offering a similar design/size, none seem to have a rating specified - I'd consider a cooler like that as a supplement, and there are a lot of rated tube and fin coolers that are shaped appropriately for frame rail [or running board] mounting
Bill
