[77newell]

I believe any turbocharged two stroke Detroit engine has a built in aftercooler after the blower. It uses coolant to cool the compressed intake air. This, combined with the bottom end of the radiator providing cooling, or heating, to the transmission is a primary reason for the outsized radiators used with these engines, the heat load is ginormous.

I would also be cautious adding an additional transmission cooler if you plan to travel in cold weather. A primary reason for using the bottom reservoir of the radiator for managing the trans temp is that HT740 series Allison do not like cold fluid and in colder temps the fluid passing through the engine coolant helps get the tranny up to the desired temperature.