Can a good 27 T radiator handle the water adequately from V6 chevy engine?
No,
Model T radiators were not pressurized like modern ones and would most likely not handle the heat put out by a v6.
I say it will handle the heat just fine.
Lincolns and Cads and Ford V8 cars of the 30's had no problems running without pressure, as did Buicks and Packards etc.
Pressurizing the cooling system raises the boiling point, it does not make it run cooler.
There are new T radiators advertised all the time on ebay that are designed to be used in such applications that are very reasonably priced. KB