another electric fan question

i commute around 60 miles one way to work in bayarea traffic in my 74 duster /6 it runs like a top due to great advice, tricks, and tips from this site iv gone through the cooling system (new rad,cap,water pump, t-stat, hoses, and fitting) my concern is i know this summer is going to be a hot one and being stuck in stopped traffic for over an hour at idle might warm things up..... should i look into an electric fan setup with adjustable thermostatic switch... or wait and see how the factory setup holds up thank you for any input, help, experiences,ect