66 Dart, 408 runs hot. HELP PLEASE!

Your measurement from pump to rad changed from 2.25 to 2.5 during the conversation. A fixed blade fan will certainly fit in there, and if you measure again and get 2.7", the Hayden 2947 clutch needs only 2.7"

With that low a cfm on the elec fans, they will prob become an air dam at 20ish mph as the car speed is having to push the fans, and any kind of flat backed shroud will also be an air deflector/ dam at speed.

As always, the temp at the rad inlet and outlets will tell a lotta the story. .Summers here.