440 overheating at idle

On another forum a few years ago, a gent who I trust as being accurate & truthful tested fan distances in & out of the shroud. He found little difference in running temperature with the fan half out of the shroud to well within the shroud. These were clutch fans, not toy plastic fans.
Thank you. The original setup was a clutch fan, original rad. I thought the car ran a bit hotter than I was comfortable (looking at the car’s gauge). Over the winter I decided to upgrade the entire system (aftermarket gauge included) and the fan was recommended by the Performance Parts dealer who dealt with a lot of racing applications. I can’t say that I am completely comfortable with a plastic fan (although they said they are good to 8000rpm), but it pulls a ton of air. My plan is to continue to tweak the system to get it where I am comfortable, and then look at a fan change to metal. After all the responses (A-Body brotherhood is awesome) I am focused on fan placement, and timing, and insuring the shroud is completely sealed to the rad to force all air through the fan as the next step. On more than one site from companies that deal with engine cooling they discussed the pros and cons with different fan designs and they advised under no circumstances should you ever use a clutch fan………… that was a surprise to me………. But some of the A-Body brotherhood recommended a clutch fan.