basic tranny cooler question

kinda of a low teck non exciting question> I need a better radiator for my 12 sec zeph. if I upgrade to a alum rad, how much does the built in tranny cooler really help? of course I already have a stand alone tranny cooler. trans is a c6, 3600 stall, 327 rear gear, 26inch tire. car is a street car night at brainerd participant along with occasional romps through rural roads in mn, wisc. thanks bobn