69 Dart cooling questions

I`m not a fan of flex fans. I`ve had a few and they never seemed to cool well. I`d get a good viscous fan of the largest diameter that`ll fit inside the shroud. Mopar`s unit is good and like Jefflock and 64cuda said, replace the 160 thermostat with something a little hotter. A water pump for an A/C car may help. A good flush of the system and a refill with fresh coolant can`t hurt either.