Big block cooling question

I know we're talking big block, but 69 340 Dart has factory underdriven pulleys. I have a 22 inch aluminium radiator with the fan shroud. And a thermostatic clutch fan. No issues. Also i have a 440 with a stock 26 inch radiator and shroud, with a stainless 18 inch fan. March underdrive pulleys. Point is, it might not be the pulleys. I eould do the cheap, and simple stuff first. Remove the electric fan. It's blocking airflow. Get the spring for the lower hose. They do collapse. Mustang suppliers sell them about 10 bucks. Pull the thermostat, and check it with a meat thermometer. I've found they can vary alot from the rating. Then try the clutch fan. It needs to be about 1/2in the shroud, with as many blades as possible. Then might check the WP housing. Some have been known to have issues.